Radioactive Materials

If you don't find the information you're looking for in the links on this page, be sure to contact the Radiation Safety Officer.

Authorization to Use Radioactive Materials

If you’re a Principal Investigator

You must apply to become an Authorized User for the use of radioactive materials in your laboratory at Princeton University. Applications are reviewed and approved by the Radiation Safety Committee or the Radiation Safety Officer (RSO). The entire authorization review and approval process typically takes 3-4 weeks.  Your radioisotope authorization will be issued for a term of five years; the renewal process is very quick and easy as long as you do not request significant changes in protocols. Contact the RSO to discuss your authorization plans and to get started with the application process.

If you need to use radioactive materials in very small quantities (usually referred to as Exempt Quantities), the authorization process may be simpler and quicker. 


If you’re an Undergrad or Grad Student, Post-Doc, or Other Staff

The Principal Investigator (PI) in charge of a laboratory is the Authorized User, i.e., the person who holds the official radioisotope authorization for the lab. Students and staff working in the PI’s lab will use radioactive materials under the PI’s authorization. If your PI is not currently authorized to use radioactive materials, your PI must either become authorized or you must find a PI who is authorized to do the type of radioisotope work you want to do and who is willing to allow you to work under his/her authorization.

Be aware that you will not be allowed to work with radioactive materials until you complete Radioactive Materials Safety training.


If You're Not Authorized to Use Radioactive Materials and Have a Short-Term Need to Perform Radioisotope Experiments

If you need to perform a very limited set of radioisotope experiments and have no plans for longer-term radioactive material use, it may be possible for you or your staff to work under the authorization of another PI.  Discuss your needs with the RSO.


Amending Your Authorizations

You (the PI) must apply for an amendment to your authorizations for any of the following circumstances:

  • To add or delete an authorized location for radioisotope use
  • To increase or decrease the authorized possession limit
  • To amend the authorized chemical or physical form
  • To amend the authorized experimental protocol or to add a new experimental protocol
  • To amend the experimental protocol to allow the in vivo or in vitro use of radioactivity in animals

Contact the RSO to discuss the amendment process.


Inactivating Your Authorizations

If there are no plans to use radioactive materials in your laboratory for an extended period (at least six months), we strongly encourage you to inactivate your authorizations. Inactivating your authorizations is not the same things as canceling your authorizations, because your authorizations can be almost immediately reactivated, within just a few days.  Inactivating your authorizations will save time and effort for both you and your lab staff and for EHS. While your authorizations are inactivated, you do not need to submit routine monthly reports to EHS, your lab personnel are not required to attend radiation safety training, EHS will not visit the lab to perform routine contamination surveys, and your lab will not be a target for regulatory inspections.   Contact the Radiation Safety Officer (RSO) to discuss the inactivation process.

NOTE: You can inactivate your authorizations even if you have an inventory of radioactive materials. EHS will collect your radioactive materials and store it in a secure location in a refrigerator or in a -4C or -20C degree freezer.

Buying & Acquiring Radioactive Materials

General Information

Princeton University is licensed by the New Jersey Department of Environmental Protection to possess and use radioactive materials. Our license conditions require that the University carefully control the process of obtaining radioactive materials to make sure that unauthorized labs and people don’t receive radioactive materials and to make sure that all radioactive materials are shipped to the correct Radioactive Receiving address.

The lab or staff member ordering the material must be authorized to possess and use radioactive materials. See Authorization to Use Radioactive Materials.


Ordering Licensed Radioactive Materials

Orders for radioactive material must be coded so that they are routed to the EHS worklist for approval:

  • For common vendors such as Perkin-Elmer or MP Biomedical, place an order through the PRIME Marketplace. The radioactive items you order through the Marketplace are coded by default as Radioactive, and the req will be routed to EHS for approval. The default shipping address for these items is the Radioactive Receiving address.
  • For vendors or items not listed in the Marketplace, place a special requisition.  Be sure that you choose the Radioactive Materials code and that you specify the Ship-To address as Radioactive Receiving.

Requesting a Free Replacement for a Bad Product

If you are not happy with the quality of the product a vendor sent you, contact EHS. EHS will then notify the Purchasing Office, and Purchasing will arrange for a free replacement shipment. Do not request a replacement shipment directly from the vendor.


Receiving Samples from a Vendor or a Collaborator

  • If a vendor offers you a free sample, notify EHS. EHS will contact the Purchasing Office to make arrangements to ship the sample.
  • If a collaborator wants to ship radioactive experimental samples to you, contact EHS prior to the sample shipment. EHS will contact the radiation safety office at the collaborator’s institution to arrange for shipping the sample.

Ordering Exempt Quantity Radioactive Materials

The U.S. Nuclear Reglatory Commission has determined that exempt quantity sources, which are radioactive sources containing very small amounts of radioactivity and used under certain conditions, do not present a significant hazard.  Example of exempt quantity sources include button sources used for instructional labs and for meter calibrations. 

Vendors are permitted to sell exempt quantity sources to any purchaser.  However, EHS makes an effort to know about all radioactive sources on our campus, including exempt quantity sources.  If you plan to buy exempt quantity sources, contact the Radiation Safety Officer to discuss the purchase and delivery of your sources.   


Generally-Licensed Devices

Generally-licensed devices (GLDs) are devices that contain radioactive materials, often with substantial amounts of radioactivity, in forms that are considered safe as long as they are not damaged and as long as certain conditions are followed by the user.  Examples include self-luminous exit signs containing H-3 (tritium), gas chromatographs containing electron capture detectors (Ni-63), antistatic devices (Po-210) and the internal standards in liquid scintillation counters (usually Cs-137).  It is often necessary:

  • to perform routine leak tests on GLDs to ensure they are not leaking, 
  • to dispose of them as radioactive waste, and,
  • to follow certain transfer procedures if you need to transfer a GLD to another user or institution.

EHS will work with you to make sure the necessary requirements are met.  If you plan to purchase a generally-licensed device or have obtained a GLD, be sure to contact the Radiation Safety Officer to discuss these requirements.


Ordering Uranium or Thorium Compounds

Certain uranium and thorium compounds, such as uranyl acetate or thorium nitrate, are regulated differently than licensed radioactive materials.  By regulation, the general public is allowed to order these materials without possessing a radioactive materials license, so vendors will sell these compounds directly to any customer.  However, educational institutions are not allowed to possess more than 3.3 pounds of uranium or thorium at any one time.  This means that Princeton University must keep track of how much uranium or thorium is present on campus.

  • Before you order uranium or thorium compounds, consult with EHS about the ordering process.
  • If you do acquire uranium or thorium compounds without contacting EHS, notify EHS as soon as possible so that EHS can list your materials on the University inventory.

Delivery of Radioactive Material Packages

All radioactive material packages are delivered to the Radioactive Receiving address at Lewis Thomas Laboratory.  EHS staff will enter information about the radioactive vial into RITA, the University's Radioisotope Inventory & Tracking database.  We will also survey each level of packaging to ensure that there is no external contamination on any part of your package or on the exterior of the vial.  The package will be delivered directly to authorized personnel in your lab.

Handling Radioactive Materials Safely


Personal Protective Clothing

  • Required PPE: For any work with an open radioactive source, wear:
    • disposable gloves (latex or nitrile gloves are generally suitable)
    • a full-length lab coat (worn closed with sleeves rolled down)
    • close-toed shoes. Never wear sandals or other open-toed shoes while working with radioactivity.
  • Safety Glasses: You should wear safety glasses for any radioisotope procedure, but it is especially important whenever there is a potential for the build-up of pressure that could release a spray of material.
  • Protecting Your Wrists: Lab coat cuffs may hang down and drag across contaminated surfaces. To protect the skin of your wrists, consider one of the following steps:
    • Wrap tape around your lab coat sleeve or put a rubber band around the sleeve to keep the cuff from dragging.
    • Wear long gloves and tuck your lab coat into the gloves.
    • Wear Tyvek sleeve protectors.
    • Survey the skin of your wrists frequently as you work.
  • Contaminated Lab Coats: See Spills & Incidents for information about how to handle a contaminated lab coat.
  • Extra Clothing: Keep an extra set of clothing and shoes in the lab in case your clothing becomes contaminated.
  • Petroleum-Based Hand Creams: Avoid using petroleum-based hand creams when wearing gloves because petroleum-based hand creams may increase glove permeability.

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Food and Beverages

  • No Eating or Drinking: Do not eat or drink in any room labeled with a Caution: Radioactive Materials sign on the door.

No eating or drinking in a Radioactive Material Room

When you see this sign on a door, you'll know that you are never permitted to eat or drink in that room.

  • No Storage: Do not store food, beverages, or medicines in refrigerators, freezers or coldrooms where radioactive materials are used or stored.
  • Storing Food & Items in Your Desk: You may store your food, water bottles, beverages, medicines, coffee mugs, eating utensils, etc. in your closed desk in a radioisotope use lab, but you are not permitted to have these items out on top of your desk or any other surfaces.   

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Security

  • Stock Vials:  Lock radioactive stock materials and sealed sources in a secured container or a secured storage area when not in use. A stock material is radioactive material as provided by the vendor and does not include material withdrawn from the original stock for experimental use.
  • Tethered Lock Box:  If you store your stock vials in a lockbox, the lockbox must be tethered to a surface with a secure cable or the lock box must either be kept in a locked freezer or refrigerator.
  • Locking the Lab: Do not leave radioactive materials unsecured in an unattended lab, even for a short time, unless the lab is locked.
  • Supervising Visitors: Supervise your own visitors to the lab.
  • Greeting Visitors: When visitors who are not accompanied by authorized lab personnel enter the lab, courteously find out who they are and why they are there.
  • Missing Materials: If you discover that radioactive material is missing or lost and cannot be accounted for, notify EHS no later than the next business day.

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Signs and Labels

  • Room Labeling: EHS labels radioisotope use rooms with Caution Radioactive Material signs. If there are no signs on a room in which radioactive materials are used or stored, contact EHS to request labeling for the room.
  • Container & Equipment Labeling: Label any container of radioactive material or piece of equipment in which radioactive material is stored and any contaminated area or item, regardless of the level of radioactivity, with Radioactive tape. Labeling contaminated items and containers of radioactive material is an important tool for contamination control and is a courtesy to other laboratory personnel.

Each lab is responsible for maintaining its own supply of Radioactive Material tape. Your department's stockroom may keep a supply.  

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Setting Up a Radioactive Materials Work Area

Absorbent Paper:  Cover the work surface with protective and absorbent bench paper to trap droplets of contamination. It's especially convenient to cover the entire work area and then to use smaller pieces on top of the large piece. It's easier to replace the small piece when it becomes contaminated than to replace the entire covering.

Dedicated Equipment:  Your radioisotope work area should have a set of equipment that is only used for radioactive material work. Depending on your protocol, this may include pipettors, a microcentrifuge, timers, mixers, a water bath, etc.

A lab bench set up with absorbent paper, dedicated pipettors and shielding

An example of a good radioactive materials work area, showing the use of absorbent paper, shielding, dedicated pipettors, and labeling of equipment.

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Good Laboratory Practices

  • Familiarity with Radioisotope Properties: Be familiar with the properties of the radioisotope you plan to use and with any precautions and concerns specific to that radioisotope and material. For instance, there are special precautions for working with 35S-methionine because of its volatility. See Radioisotope Fact Sheets for detailed information about the radioisotopes most commonly used at the University.
  • Rehearsing Procedures: Rehearse unfamiliar radioisotope procedures before radioactive material is actually used. This helps you to see where all the necessary materials should be placed; it helps you to work efficiently; and it helps you to identify moments during the procedure when aerosols or contamination is most likely to occur.
  • Preoperational Survey: Are you sure your work area is free of contamination when you start? You are encouraged to survey your work area carefully before you start in case someone else left the work area contaminated or in case you missed contamination the last time you worked.
  • Radiation Monitoring Badges: Wear radiation monitor badges when appropriate. Wear ring badges under gloves to prevent the ring from getting contaminated. Make sure you don't discard the ring when you remove your gloves.
  • Changing Gloves: Change your gloves frequently. Your radioactive solutions, especially when aliquoting from the stock vial, are likely to be highly concentrated. It is very easy to contaminate your gloves and to spread contamination.
  • Mouth Pipetting: Never pipette radioactive materials by mouth.
  • Surveys While You Work: Even though you are only required to do a postoperational survey, it is very good practice to survey frequently and extensively as you work. Don't assume that contamination will only be found on the bench top.
  • O-Rings: if you are relying on tubes with o-rings to contain your radioactive material (during hybridizations, for instance), be sure to check the condition of the tubes to be sure the o-rings aren't dried out. 
  • Volatile Radioactivity: Work in a hood during procedures using volatile materials such as I-125 or S-35 methionine/cysteine.
  • Waste: Cover radioactive waste cans at all times and store waste cans away from areas in which people spend substantial amounts of time. Provide shielding for waste cans with significant external radiation levels.
  • Postoperational Surveys: Survey yourself and your clothing when radioisotope work is finished and before leaving the lab.

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Microcentrifuge Use

It is difficult to keep a microcentrifuge used for radioactive material work free of contamination. Contaminated microcentrifuges must be cleaned up after use to prevent contamination from spreading to other tubes and to your gloves. The following steps may help reduce the incidence of contamination:

  • Wipe down the exterior of the tubes before placing them in the microfuge.
  • Don't fill tubes more than 2/3 full.
  • Use tubes with locking caps or with screwcaps (the type with O-rings).
  • Consider using an aerosol-tight rotor so that only the interior of the rotor becomes contaminated.

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Fume Hoods and Biosafety Cabinets

Work with certain radioactive materials, such as volatile I-125 or millicurie amounts of S-35 methionine/cysteine, must be performed in a designated radioactive materials (RAM) fume hood. Do not use biological safety cabinets (or laminar flow hoods) for work with volatile radioactive materials, since the air from the cabinet may be exhausted back to the room.

Visit the Laboratory Safety Page on Fume Hoods for detailed information about using your fume hood properly. 

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Radioisotope Fact Sheets

These fact sheets provide information about each radioisotope's physical characteristics (half-life, emissions and energies), dose rates and shielding needs,  detection requirements, special precautions, and waste disposal requirements.  If you need a fact sheet for a radioisotope not listed here, contact the Radiation Safety Officer.

Hydrogen -3 (Tritium)

Physical Characteristics

  • Half-life: 12.3 years
  • Emissions: Beta particles with a maximum energy of 18.6 keV and an average energy of 5.7 keV.
  • Maximum Range: 4.7 mm in air; 0.006 mm in tissue
  • Fraction transmitted through the dead layer of the skin: none

Dose Rate and Shielding

  • Dose rate to the skin at 10 cm: None
  • Dose rate to epidermal basal cells from skin contamination of 1 mCi/cm2: None
  • Shielding: None needed.
  • Annual Limit on Intake (ALI): 80 millicuries via ingestion, assuming intake as tritiated water. The ingestion of one ALI will produce a dose of 5 rem.

Detection

Liquid scintillation counting is the preferred method for detecting H-3. Most G-M detectors will not detect the presence of H-3.

Precautions

H-3 contamination cannot be detected with a G-M meter, and special precautions are needed to keep the work environment clean. The regular use of wipe testing, using a liquid scintillation counter, is the only way to insure that your work space does not contain contamination.

Waste Disposal

  • Solid Wastes/Liquid Scintillation Wastes: through the Off-Site Radioactive Waste Disposal Program
  • Liquid Wastes: through the Sewer Disposal Program. The laboratory disposal limit for H-3 is 3 mCi per month.

Carbon-14

Physical Characteristics

  • Half-life: 5,730 years
  • Emissions: Beta particles with a maximum energy of 156 keV and an average energy of 49 keV.
  • Maximum Range: 22 cm in air; 0.027 cm in tissue
  • Fraction transmitted through the dead layer of the skin: 0.11

Dose Rate and Shielding

  • Dose rate to the skin at 10 cm: 600 mrad/hour/mCi (for an unshielded point source)
  • Dose rate to epidermal basal cells from skin contamination of 1 mCi/cm2: 1400 mrad/hour
  • Shielding: None needed, when used in millicurie quantities under normal laboratory conditions.
  • Annual Limit on Intake (ALI): 2 millicuries via ingestion. The ingestion of one ALI will produce a dose of 5 rem.

Detection

Wipe surveys using liquid scintillation counting is the preferred method for detecting C-14. Most G-M detectors are not likely to detect the presence of C-14 in amounts less than about 100,000 dpm (0.05 µCi).

Precautions

Low-level C-14 contamination cannot be easily detected with a G-M meter, and special precautions are needed to keep the work environment clean. The regular use of wipe testing, using a liquid scintillation counter, is the only way to insure that your work space does not contain low-level removable contamination.

Waste Disposal

  • Solid Wastes/Liquid Scintillation Wastes: through the Off-Site Radioactive Waste Disposal Program
  • Liquid Wastes: through the Sewer Disposal Program. The laboratory disposal limit for C-14 is 3 mCi per month.

Phosphorus-32

Physical Characteristics

  • Half-life: 14.3 days
  • Emissions: Beta particles with a maximum energy of 1.71 MeV and an average energy of 0.7 MeV.
  • Maximum Range: 620 cm in air; 0.8 cm in tissue; 0.6 cm in plexiglas
  • Fraction transmitted through the dead layer of the skin: 0.95

Dose Rate and Shielding

  • Dose rate to the skin at 10 cm: 4070 mrad/hour/mCi (for an unshielded point source)
  • Dose rate to epidermal basal cells from skin contamination of 1 mCi/cm2: 9200 mrad/hour
  • Shielding: 3/8” plexiglas/lucite will shield all P-32 betas. For high activity sources exceeding a few millicuries, it may be desirable to add lead shielding outside the plexiglas shielding to shield against bremsstrahlung x-rays. Plexiglas should be placed closest to the P-32 source as primary shielding, and lead should be used outside the plexiglas as secondary shielding.
  • Annual Limit on Intake (ALI): 600 microcuries via ingestion. The intake of one ALI will produce a dose of 5 rem.

Detection

A G-M detector will readily detect low-level P-32 contamination, although liquid scintillation counting is also an acceptable method for detecting removable P-32 contamination.

Precautions

High localized doses are possible while handling millicurie amounts of P-32 and as a result of skin contamination. Reduce doses by wearing safety glasses (for shielding the eyes), using remote handling tools such as tongs, using shielding extensively to shield storage and experimental containers and work areas, and performing thorough and frequent surveys of the work area, clothing and the body.

Radiation Monitoring Requirements: Radiation monitoring badges must be worn by any person who uses open sources of P-32 in amounts of 5 mCi or more for extended operations (applies to most operations other than simple aliquoting from a stock vial).

Waste Disposal

  • Solid Wastes: through the Onsite Decay-in-Storage Program
  • Liquid Scintillation Wastes:  through the Off-Site Radioactive Waste Disposal Program
  • Liquid Wastes: through the Sewer Disposal Program. The laboratory disposal limit for P-32 is 0.3 mCi per month.

Silicon-32

Physical Characteristics

  • Half-life: 104 years
  • Emissions: Beta particles with a maximum energy of 0.224 MeV and an average energy of 0.067 MeV. Since Si-32 decays to P-32, emissions from a Si-32 source also include the 1.71 MeV beta from P-32
  • Maximum Range: 37 cm in air; <.05 cm in tissue.
  • See the P-32 fact sheet for information about the properties of the beta from the P-32 progeny.

Dose Rate and Shielding

  • Dose rate to the skin at 10 cm: See the P-32 fact sheet for information about the dose from the P-32 progeny.
  • Dose rate to epidermal basal cells from skin contamination of 1 µCi/cm2: See the P-32 fact sheet for information about the dose from the P-32 progeny.
  • Shielding: Depending on the age of the material, plexiglas shielding may be required for the P-32 progeny.
  • Annual Limit on Intake (ALI): 2000 microcuries via ingestion and 200 microcuries via inhalation. The intake of one ALI will produce a dose of 5 rem.

Detection

A G-M detector will readily detect low-level P-32 contamination, although wipe surveys using liquid scintillation counting is also an acceptable method for detecting removable P-32 contamination.

Precautions

High localized doses are possible while handling millicurie amounts of P-32 and as a result of skin contamination. Reduce doses by wearing safety glasses (for shielding the eyes), using remote handling tools such as tongs, using shielding extensively to shield storage and experimental containers and work areas, and performing thorough and frequent surveys of the work area, clothing and the body.

Waste Disposal

  • Solid Wastes: through the Onsite Decay-in-Storage Program
  • Liquid Scintillation Wastes:  through the Off-Site Radioactive Waste Disposal Program
  • Liquid Wastes: through the Sewer Disposal Program. The laboratory disposal limit for P-32 is 0.3 mCi per month.

Phosphorus-33

Physical Characteristics

  • Half-life: 25.3 days
  • Emissions: Beta particles with a maximum energy of 249 keV and an average energy of 76 keV.
  • Maximum Range: 45 cm in air; 0.06 cm in tissue
  • Fraction transmitted through the dead layer of the skin: 0.35

Dose Rate and Shielding

  • Dose rate to the skin at 10 cm: 2000 mrad/hour/mCi (for an unshielded point source)
  • Dose rate to epidermal basal cells from skin contamination of 1 mCi/cm2: 4500 mrad/hour
  • Shielding: None needed, when used in millicurie quantities or less, under normal laboratory conditions
  • Annual Limit on Intake (ALI): 6 millicuries via ingestion. The intake of one ALI will produce a dose of 5 rem.

Detection

Wipe surveys using liquid scintillation counting is the preferred method for detecting P-33. Most G-M detectors are not likely to detect the presence of P-33 in amounts less than about 100,000 dpm (0.05 µCi).

Precautions

Low-level P-33 contamination cannot be easily detected with a G-M meter, and special precautions are needed to keep the work environment clean. The regular use of wipe testing, using a liquid scintillation counter, is the only way to insure that the work space does not contain low-level removable contamination.

Waste Disposal

  • Solid Wastes: through the Onsite Decay-in-Storage Program
  • Liquid Scintillation Wastes:  through the Off-Site Radioactive Waste Disposal Program
  • Liquid Wastes: through the Sewer Disposal Program. The laboratory disposal limit for P-33 is 3 mCi per month.

Sulfur-35

Physical Characteristics

  • Half-life: 87.6 days
  • Emissions: Beta particles with a maximum energy of 167 keV and an average energy of 49 keV.
  • Maximum Range: 24 cm in air; 0.030 cm in tissue.
  • Fraction transmitted through the dead layer of the skin: 0.12

Dose Rate and Shielding

  • Dose rate to the skin at 10 cm: 625 mrad/hour/mCi (for an unshielded point source)
  • Dose rate to basal cells from skin contamination of 1 mCi/cm2: 1460 mrad/hr
  • Shielding: None needed, when used in millicurie quantities under normal laboratory conditions
  • Annual Limit on Intake (ALI): 10 millicuries via ingestion for most compounds of sulfur. The intake of one ALI will produce a dose of 5 rem.

Detection

Wipe surveys using liquid scintillation counting is the preferred method for detecting S-35. Most G-M detectors are not likely to detect the presence of S-35 in amounts less than about 100,000 dpm (0.05 µCi).

Precautions

  • 35S-labeled methionine/cysteine compounds can volatilize. Stock solutions and thawed materials should be opened within a fume hood. Activated charcoal can be used to trap contamination within equipment such as incubators. Contact EHS for further information.
  • Low-level S-35 contamination cannot be easily detected with a G-M meter, and special precautions are needed to keep the work environment clean. The regular use of wipe testing, using a liquid scintillation counter, is the only way to insure that the work space does not contain low-level removable contamination.

Waste Disposal

  • Solid Wastes: through the Onsite Decay-in-Storage Program
  • Liquid Scintillation Wastes:  through the Off-Site Radioactive Waste Disposal Program
  • Liquid Wastes: through the Sewer Disposal Program. The laboratory disposal limit for S-35 is 3 mCi per month.

Iron-55

Physical Characteristics

  • Half-life: 2.70 years
  • Emissions: Principal emissions are a 6 keV x-ray and 5.2 keV [average] Auger electrons.
  • Electron Maximum Range: 0.15 cm in air; 0.0 cm in tissue

Dose Rate and Shielding

  • Dose rate at 10 cm: negligible
  • Dose rate to basal cells from skin contamination of 1 µCi/cm2: 59 mrem/hr
  • Shielding: None needed, when used in millicurie quantities, under normal laboratory operations.
  • Annual Limit on Intake (ALI): 2,000 microcuries via inhalation, and 9,000 microcuries via ingestion. The intake of one ALI will produce a dose of 5 rem.

Detection

Liquid scintillation counting is the preferred method for detecting Fe-55 contamination, although a low energy sodium iodide crystal scintillation detector will also detect Fe-55 with a lower efficiency. The regular use of wipe testing, using a liquid scintillation counter, is the only way to insure that the work space does not contain low-level removable contamination.

Precautions

External radiation from Fe-55 is low energy and does not normally present an external exposure hazard. Low-level Fe-55 contamination is not readily detected with a survey meter, and special precautions are needed to keep the work environment clean. The regular use of wipe testing, using a liquid scintillation counter, is the only way to insure that your work space does not contain low-level removable contamination.

Radiation Monitoring Requirements: Radiation monitoring badges are not required for Fe-55 users.

Waste Disposal

  • Solid Wastes/Liquid Scintillation Wastes:  through the Off-Site Radioactive Waste Disposal Program
  • Liquid Wastes: through the Sewer Disposal Program. The laboratory disposal limit for Fe-55 is 3 mCi per month.

Iron-59

Physical Characteristics

  • Half-life: 44.6 days
  • Emissions:
    • Beta particles: 0.273 MeV (46%) and 0.466 MeV (53%) maximum energies with average energies of 0.081 MeV and 0.149 MeV respectively.
    • Gamma rays: 1.099 MeV (56%) and 1.292 MeV (44%).
  • Beta Maximum Range: ~ 100 cm in air; 0.14 cm in tissue; 0.12 cm in plexiglas
  • Fraction transmitted through the dead layer of the skin: 0.95
  • Half-Value Layer: 15 mm lead. The half-value layer is the amount of material required to reduce the radiation intensity by 50%.

Dose Rate and Shielding

  • Gamma dose rate (deep tissue dose) at 30 cm: 7.0 mrem/hour/mCi (for an unshielded point source)
  • Beta dose rate to the skin at 30 cm: 130 mrem/hour/mCi (for an unshielded point source)
  • Dose rate to epidermal basal cells from skin contamination of 1 µCi/cm2: 3593 mrem/hour
  • Shielding: Generally, lead is the preferred shielding material for Fe-59 for lower activity operations. However, it may be desirable to use a combination of plexiglas and lead/steel as shielding when working with multi-millicurie amounts to minimize the amount of bremsstrahlung produced by the betas. In such a case, plexiglas should be placed closest to the source as primary shielding, and lead should be used outside the plexiglas as secondary shielding.
  • Annual Limit on Intake (ALI): 800 microcuries via ingestion and 300 microcuries via inhalation. The intake of one ALI will produce a dose of 5 rem.

Detection

A sodium iodide crystal scintillation detector is the preferred method for detecting Fe-59. Additionally a G-M detector will readily detect Fe-59 contamination, although liquid scintillation counting is also an acceptable method for detecting removable contamination.

Precautions

High localized doses are possible while handling Fe-59 and as a result of skin contamination. Reduce doses by wearing safety glasses (for shielding the eyes), using remote handling tools such as tongs, using shielding extensively to shield storage and experimental containers and work areas, and performing thorough and frequent surveys of the work area, clothing and the body.

Radiation Monitoring Requirements: Radiation monitoring badges must be worn by any person who uses open sources of Fe-59 in amounts of 0.5 mCi or more for extended operations (applies to most operations other than simple aliquoting from a stock vial).

Waste Disposal

  • Solid Wastes: through the Onsite Decay-in-Storage Program
  • Liquid Scintillation Wastes:  through the Off-Site Radioactive Waste Disposal Program
  • Liquid Wastes: through the Sewer Disposal Program. The laboratory disposal limit for Fe-59 is 0.3 mCi per month.

Nickel-63

Physical Characteristics

  • Half-life: 100.1 years
  • Emissions: Beta particles with a maximum energy of 66 keV and an average energy of 17 keV
  • Maximum Range: 5 cm in air; < 0.01 cm in tissue

Dose Rate and Shielding

  • Dose rate to the skin at 10 cm: negligible (for an unshielded point source)
  • Dose rate to epidermal basal cells from skin contamination of 1 µCi/cm2: negligible
  • Shielding: None needed.
  • Annual Limit on Intake (ALI): 9000 microcuries via ingestion and 2000 microcuries via inhalation. The ingestion of one ALI will produce a dose of 5 rem. 

Detection

A wipe survey using liquid scintillation counting is the preferred method for detecting Ni-63. G-M detectors will not detect Ni-63 contamination

Precautions

Ni-63 contamination cannot be detected with a G-M meter, and special precautions are needed to keep the work environment clean. The regular use of wipe testing, using a liquid scintillation counter, is the only way to insure that your work space does not contain low-level removable contamination.

Radiation Monitoring Requirements: Radiation monitoring badges are not required for Ni-63 users, since the monitoring badges will not detect Ni-63.

Waste Disposal

  • Solid Wastes/Liquid Scintillation Wastes: through the Off-Site Radioactive Waste Disposal Program
  • Liquid Wastes: through the Sewer Disposal Program. The laboratory disposal limit for Ni-63 is 3 mCi per month.

Zinc-65

Physical Characteristics

  • Half-life: 243.9 days
  • Emissions: Beta (positron) particles with a maximum energy of 0.33 MeV (2%) and an average energy of 0.099 MeV. Gamma rays: 1.116 MeV (51%) and 0.511 MeV (2%).
  • Beta Maximum Range: 76.2 cm in air; 0.10 cm in tissue; 0.08 cm in plexiglas
  • Fraction transmitted through the dead layer of the skin: 0.95
  • Half-Value Layer: 14 mm lead; 2 cm in tissue.  The half-value layer is the amount of material required to reduce the radiation intensity by 50%.

Dose Rate and Shielding

  • Beta Dose rate to the skin at 30 cm: 1.93 mrem/hour/mCi (for an unshielded point source)
  • Gamma Dose rate (deep tissue dose) at 30 cm: 3.44 mrem/hour/mCi (for an unshielded point source)
  • Dose rate to epidermal basal cells from skin contamination of 1 µCi/cm2: 281 mrem/hour
  • Shielding: Shield stock vials with lead. Generally, lead is the preferred shielding material for Zn-65 for lower activity operations. However, since significant bremsstrahlung may be produced with higher activities, it may be desirable to use a combination of plexiglas and lead/steel as shielding when working with multi-millicurie amounts. In such a case, plexiglas should be placed closest to the source as primary shielding, and lead should be used outside the plexiglas as secondary shielding.
  • Annual Limit on Intake (ALI): 400 microcuries via ingestion and 300 microcuries via inhalation. The intake of one ALI will produce a dose of 5 rem.

Detection

A G-M detector will readily detect low-level Zn-65 contamination, although liquid scintillation counting is also an acceptable method for detecting removable contamination.

Precautions

High localized doses are possible while handling millicurie amounts of Zn-65 and as a result of skin contamination. Reduce doses by wearing safety glasses (for shielding the eyes), using remote handling tools such as tongs, using shielding extensively to shield storage and experimental containers and work areas, and performing thorough and frequent surveys of the work area, clothing and the body.

Radiation Monitoring Requirements: Radiation monitoring badges must be worn by any person who uses open sources of Zn-65 in amounts of 0.5 mCi or more for extended operations (applies to most operations other than simple aliquoting from a stock vial).

Waste Disposal

  • Solid Wastes & Liquid Scintillation Wastes: through the Off-Site Radioactive Waste Disposal Program
  • Liquid Wastes: through the Sewer Disposal Program. The laboratory disposal limit for Zn-65 is 0.3 mCi per month.

Selenium-75

Physical Characteristics

  • Half-life: 119.8 days
  • Emissions: Principal emissions are 136 keV and 265 keV x-rays.
  • Half-Value Layer: 0.02 mm lead; 2 cm in tissue (The half-value layer is the amount of material required to reduce the radiation intensity by 50%.)

Dose Rate and Shielding

  • Gamma Dose rate (deep tissue dose) at 30 cm: 2.74 mrem/hour/mCi (for an unshielded point source)
  • Dose rate to epidermal basal cells from skin contamination of 1 µCi/cm2: 519 mrem/hour
  • Shielding: Lead foil or sheets, when used in hundreds of microcuries or in millicurie quantities. None needed when used in low microcurie amounts.
  • Annual Limit on Intake (ALI): 700 microcuries via inhalation, and 500 microcuries via ingestion. The intake of one ALI will produce a dose of 5 rem.

Detection

A sodium iodide crystal scintillation detector is the preferred method for detecting Se-75. Additionally a G-M detector will readily detect Se-75 contamination, although liquid scintillation counting is also an acceptable method for detecting removable contamination.

Precautions

High localized doses are possible while handling millicurie amounts of Se-75 and as a result of skin contamination. Reduce doses by using remote handling tools such as tongs, using shielding extensively to shield storage and experimental containers and work areas, and performing thorough and frequent surveys of the work area, clothing and the body.

Radiation Monitoring Requirements: Radiation monitoring badges must be worn by any person who uses open sources of Se-75 in amounts of 0.5 mCi or more for extended operations (applies to most operations other than simple aliquoting from a stock vial).

Waste Disposal

  • Solid Wastes: through the Onsite Decay-in-Storage Program
  • Liquid Scintillation Wastes:  through the Off-Site Radioactive Waste Disposal Program
  • Liquid Wastes: through the Sewer Disposal Program. The laboratory disposal limit for Se-75 is 3 mCi per month.

Cadmium-109

Physical Characteristics

  • Half-life: 462.6 days
  • Emissions: Principal emissions are 22.1 keV x-rays (83%), accompanied by electrons with energies ranging up to 87 keV.
  • Half-Value Layer: 0.01 mm lead; 2 cm in tissue (The half-value layer is the amount of material required to reduce the radiation intensity by 50%.)

Dose Rate and Shielding

  • Dose rate to the skin at 10 cm: 0 mrem/hour/mCi (for an unshielded point source)
  • Gamma Dose rate (deep tissue dose) at 30 cm: 0.778 mrem/hour/mCi (for an unshielded point source)
  • Dose rate to epidermal basal cells from skin contamination of 1 µCi/cm2: 2000 mrem/hour
  • Shielding: Lead foil or sheets are used to shield the x-rays (the electrons are too low in energy to require shielding) when Cd-109 is used in hundreds of microcuries or in millicurie quantities. Shielding is not needed when Cd-109 is used in low microcurie amounts.
  • Annual Limit on Intake (ALI): 40 microcuries via inhalation, and 300 microcuries via ingestion. The intake of one ALI will produce a dose of 5 rem. The critical organ for protection are the kidneys.

Detection

A sodium iodide crystal scintillation detector is the preferred method for detecting Cd-109. G-M detectors are not likely to detect the presence of Cd-109 in amounts less than about 100,000 dpm (0.05 µCi).

Precautions

Skin contamination and ingestion are the chief concerns when working with Cd-109, and appropriate precautions must be taken to limit contamination. Contamination of work areas and individuals is a more significant hazard than the external dose, unless working with millicurie quantities.

Radiation Monitoring Requirements: Radiation monitoring badges must be worn by any person who uses open sources of Cd-109 in amounts of 1 mCi or more for extended operations (applies to most operations other than simple aliquoting from a stock vial).

Waste Disposal

  • Solid Wastes/ Liquid Scintillation Wastes:  through the Off-Site Radioactive Waste Disposal Program
  • Liquid Wastes: through the Sewer Disposal Program. The laboratory disposal limit for Cd-109 is 0.3 mCi per month.

Iodine-125

Physical Characteristics

  • Half-life: 60.1 days
  • Emissions: Principal emissions are a 35 keV gamma ray and 27 - 32 keV x-rays.
  • Half-Value Layer: 0.02 mm lead; 2 cm in tissue. (The half-value layer is the amount of material required to reduce the radiation intensity by 50%.)

Dose Rate and Shielding

  • Dose rate at 10 cm: 15 mrem/hour/mCi (for an unshielded point source)
  • Shielding: Lead foil or sheets, when used in hundreds of microcuries or in millicurie quantities. None needed when used in low microcurie amounts such as for RIA kits.
  • Annual Limit on Intake (ALI): 60 microcuries via inhalation, and 40 microcuries via ingestion. The intake of one ALI will produce a dose of 5 rem. The critical organ for protection is the thyroid gland.

Detection

A sodium iodide crystal scintillation detector is the preferred method for detecting I-125. G-M detectors are not likely to detect the presence of I-125 in amounts less than about 100,000 dpm (0.05 µCi).

Precautions

Volatile iodine can be released from Na125I or from iodinated compounds containing hundreds of microcuries or more of I-125. Containers of I-125, including sample vials of iodinated compounds, should always be opened in a fume hood. Personnel using I-125 in hundreds of microcuries or more must wear double gloves and should change gloves as soon as the gloves become contaminated. Iodinations must be performed under EHS surveillance and thyroid count bioassays must be performed following an iodination.

Waste Disposal

  • Solid Wastes: through the Onsite Decay-in-Storage Program
  • Liquid Scintillation Wastes:  through the Off-Site Radioactive Waste Disposal Program
  • Liquid Wastes: through the Sewer Disposal Program. The laboratory disposal limit for I-125 is 0.03 mCi per month.

Mercury-203

Physical Characteristics

  • Half-life: 47 days
  • Emissions:
    • Beta particles: 0.210 MeV maximum energy (100 %) and 0.070 MeV average energy.  Beta Maximum Range: 34 cm in air; 0.04 cm in tissue; 0.04 cm in plexiglas
    • Gamma rays: 0.279 MeV (100%).

Dose Rate and Shielding

  • Dose rate to the skin at 30 cm: 15.2 mrem/hour/mCi (for an unshielded point source)
  • Gamma Dose rate (deep tissue dose) at 30 cm: 1.63 mrem/hour/mCi (for an unshielded point source)
  • Dose rate to epidermal basal cells from skin contamination of 1 µCi/cm2: 3296 mrem/hour
  • Shielding: Shield stock vials with lead.
  • Half-Value Layer: 0.2 cm lead (The half-value layer is the amount of material required to reduce the radiation intensity by 50%.)
  • Annual Limit on Intake (ALI): 500 microcuries via ingestion and 800 microcuries via inhalation. The intake of one ALI will produce a dose of 5 rem. 

Detection

A G-M detector will readily detect low-level Hg-203 contamination, although a wipe survey using liquid scintillation counting is also an acceptable method for detecting removable contamination.

Precautions

High localized doses are possible while handling millicurie amounts of Hg-203 and as a result of skin contamination. Reduce doses by wearing safety glasses (for shielding the eyes), using remote handling tools such as tongs, using shielding extensively to shield storage and experimental containers and work areas, and performing thorough and frequent surveys of the work area, clothing and the body.

Radiation Monitoring Requirements: Radiation monitoring badges must be worn by any person who uses open sources of Hg-203 in amounts of 0.5 mCi or more for extended operations (applies to most operations other than simple aliquoting from a stock vial).

Waste Disposal

  • Solid Wastes: through the Onsite Decay-in-Storage Program
  • Liquid Scintillation Wastes:  through the Off-Site Radioactive Waste Disposal Program
  • Liquid Wastes: through the Sewer Disposal Program. The laboratory disposal limit for Hg-203 is 3 mCi per month.

Contamination Surveys


Frequent surveys performed by knowledgeable laboratory personnel are the main line of defense to detect spills and to prevent the spread of contamination within and beyond the laboratory. EHS performs monthly contamination surveys in active radioisotope-using labs, but the EHS surveys are intended to verify that no contamination exists. EHS rarely finds contamination, because researchers do a very good job of performing postoperational surveys and cleaning up any contamination that occurs.  

This section summarizes the requirements for performing surveys and provides some guidance about how to perform a survey.  EHS provides hands-on training in how to use a survey meter to people who attend the Radioactive Materials Safety Class.


Types of Contamination

Removable contamination can be readily removed without using destructive decontamination procedures. Removable contamination in any amount may present both an external and internal hazard because it can be picked up on skin and possibly ingested.

Fixed contamination cannot be readily decontaminated. For instance, contamination that has chemically bonded to a surface is fixed.  Fixed contamination generally does not present a significant hazard unless the material comes loose or is present in such large amounts that it presents an external radiation hazard.

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Types of Surveys

Meter surveys, using Geiger detectors or scintillation probes, can identify gross contamination (total contamination consisting of both fixed and removable contamination) but will detect only certain radioisotopes.

Wipe surveys, using “wipes” counted on a liquid scintillation counter or a gamma counter, can identify removable contamination only but will detect most radioisotopes used at Princeton. Wipe tests are the most versatile and most sensitive method of detecting low-level contamination in the laboratory.

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What Type of Survey Instrumentation Should You Use?

The type of survey you perform to detect contamination depends on the radioisotope you are using.

  • G-M Survey Meter: Use a Geiger-Muller (G-M) survey meter to survey for P-32 (a high energy beta emitter), and other high energy beta and gamma emitters, such as Co-60, Zn-65, Cs-137, and U-238. A G-M meter can also be used to identify areas heavily contaminated with moderate energy betas, such as C-14 or S-35.  However, the G-M detector has a low efficiency for detecting these moderate energy betas, so it won't detect C-14, S-35, or P-33 in amounts less than about 100,000 dpm. G-M meters should also not be used to survey for I-125 contamination, since G-M meters will detect I-125 only when there are very high levels of contamination.

A G-M survey meter with a pancake detector

A G-M survey meter with a pancake detector

  • NaI Scintillation Survey Meter: Use a portable thin crystal NaI scintillation survey meter to survey for I-125 contamination and to conduct surveys around low-energy x-ray sources such as x-ray diffractometers and electron microscopes.

A meter with a low-energy sodium iodide detector

A meter with a low-energy sodium iodide scintillation detector

  • Liquid Scintillation Counter: The liquid scintillation counter, used for counting wipe tests, is not portable but is the most versatile counting instrument because it has a high counting efficiency for a wide range of radionuclides.
  • Gamma counters are not portable and are used to count wipe tests for photon emitters, such as Cr-51 or I-125.

The following table summarizes the instrumentation and method of choice for the isotopes most commonly used at Princeton University.

Radioisotope Acceptable Survey Method Comments
H-3 LSC There are no other acceptable survey methods
C-14 G-M or LSC LSC is most sensitive; G-M detects moderate to high levels of contamination; do not cover G-M with parafilm
P-32 G-M or LSC G-M detects low levels of contamination
P-33 G-M or LSC LSC is most sensitive; G-M detects moderate to high levels of contamination; do not cover G-M with parafilm
S-35 G-M or LSC LSC is most sensitive; G-M detects moderate to high levels of contamination; do not cover G-M with parafilm.
Zn-65 G-M or g  
I-125 NaI, g, or LSC  
U-238 G-M or LSC  

Table Key:
G-M = Survey meter with a Geiger-Muller detector
LSC = wipe survey with liquid scintillation counting
NaI = survey meter with a thin crystal sodium iodide detector
g = wipe survey with gamma counter

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How to Perform a Meter Survey

Preoperational Meter Check

Always perform an operational check the first time you use the meter each day or when you suspect it may have been misused, damaged or contaminated.

  • Battery Check: Check the survey meter’s battery by turning the meter knob to the battery test position. If the battery is adequately charged, the meter needle will swing to the battery test position on the meter face. Replace the batteries if the batteries are low (usually two D-cell batteries).
  • Background Measurement: Take the meter to an area away from sources of radiation and note the meter background reading. Typically, the background for a G-M meter with a pancake survey probe should be less than 100 counts per minute (cpm) while the background reading for a meter with a NaI scintillation crystal should be less than 300 cpm. If the meter’s background reading is substantially greater than expected, confirm that there are no unexpected sources of radiation or radioactive materials in the vicinity, and then call EHS to report a contaminated meter.
  • Source Check: Look at the calibration sticker on the side of the meter and note what the expected reading for the operational check source should be. Turn the meter on and turn the meter’s multiplier switch to a setting that will measure the check source and will provide a mid-scale reading but will not cause the needle to swing beyond full scale. For a Ludlum G-M survey meter the multiplier knob should generally be set to the X1 position. Place the probe firmly against the check source on the side of the meter and note the meter response. If the observed meter response differs from the expected response by more than 20%, the meter should be considered nonfunctional.  Call EHS to arrange for repair.

Go to the Resources box at the top of this page to view the Preoperational Check Slideshow.

To Perform the Survey

  • No Parafilm: Do not cover the probe surface with parafilm or other protective covering. Parafilm and similar materials will shield the low energy betas from C-14, P-33 and S-35 and will prevent the meter from detecting contamination.
  • Survey Slowly: Slowly move the probe about 1 centimeter above the area of interest. If you move too quickly, you may miss a small area of contamination.
  • Surveying by Sound: The pitch of the sound (the number of clicks) emitted by the detector increases as the count rate increases. It is important to know that the pitch is independent of the scale on which the meter is set. This means that you hear the same amount of clicks whether you are on the X0.1 or X1 or X10 or X100 scale.  If you survey by sound, you can look at the surface as you survey rather than constantly watching the meter face.
  • Finding Contamination: If an item or area with a sustained count rate more than three times background is found, the item or area should be considered to be contaminated.
  • Labeling: Immediately label the area or item and promptly decontaminate it. Decontamination procedures are provided in Section 1. If an area cannot be decontaminated, the contaminated area should be marked and labeled to indicate the isotope, date and level of contamination.
  • Ambiguous Readings: Sometimes, especially in the presence of other radioactive materials, the meter survey may be equivocal. When the meter survey indicates that low level contamination may be present, a wipe survey should be performed to confirm or disprove the presence of contamination.
  • Recording the Survey: Document the survey results whenever contamination is discovered or if 250 µCi or more have been handled. Record survey results in the laboratory survey log. This is a University requirement.

Using a small filter to wipe the apron of a hood

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How to Perform a Wipe Survey

Perform wipe surveys when:

  • H-3 or Fe-55 are used
  • C-14, P-33, and S-35 are used, to confirm whether removable low-level contamination exists
  • a meter survey suggests that low level contamination may be present. The wipe survey will confirm whether contamination is present or not.

The procedure for performing the survey:

  1. Using a piece of filter paper (about 1” in diameter), Q-tip or other swab, or any other absorbent material, wipe the area being surveyed. If the area is very large, subdivide it into smaller areas and use several wipes to better pinpoint the location of contamination. For some absorbent surfaces, including skin and clothing, moisten the wipe with water to increase the possibility of picking up contamination.
  2. Prepare the sample for counting as suggested in the counter’s operating manual. Analyze the wipe samples in a liquid scintillation counter for H-3 and other beta emitters and preferably in a gamma counter for Cr-51 and I-125.
  3. Sample activity is determined by dividing the sample count by the counter’s efficiency for the isotope in question. The counter’s operating manual should provide information about efficiencies and activity determination.

Call EHS with questions about liquid scintillation and gamma counter use.

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Definition of Contamination

If an item or area with a sustained count rate of three times background or greater is found, the item or area should be considered to be contaminated.

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When and Where to Survey

When to Survey

Laboratory personnel must conduct individual work area surveys (surveys of floors, workbenches, handles, experimental equipment, etc.) and personal surveys (surveys of one’s person and clothing) under the following conditions:

  • at the end of an experimental procedure;
  • at the end of each day for multi-day procedures;
  • frequently during the manipulation of millicurie quantities of open sources;
  • following the opening of radioactive material packages;
  • following withdrawals from stock vials containing more than 1 mCi;
  • Prior to exiting the laboratory (for personal surveys)

Where to Survey

Survey areas where splashes or spills may have occurred and areas where a person could unknowingly transfer contamination. Typical survey locations include:

  • Bench tops, including the edges
  • Fume hoods (aprons, sashes, sash handles)
  • Beta shields
  • Refrigerator and freezer door handles
  • Sinks designated for radioactive material disposal (sink basin, surrounding bench, faucet handles)
  • Floors: at working areas, laboratory entrances, waste containers, fume hoods
  • Communal equipment, such as pipettors, timers, incubators, centrifuges, water baths, etc.
  • Non-radioactive trash (to ensure that contaminated waste is not disposed of as regular trash)
  • Clean areas (offices, desks, doorknobs, phones, computers)

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Documenting Surveys

When to Document Surveys

Document the survey results:

  • when radioactivity in amounts of 250 µCi or more have been handled,
  • whenever contamination is discovered, regardless of the amount used, and
  • to show follow-up actions, whenever contamination has been cleaned up.ow to Document Surveys

How to Document Surveys

Record survey results in the Laboratory Contamination Survey Log. Each log entry should contain the following information:

  • Name of person performing the survey
  • Date of survey
  • Brief description of the area surveyed
  • Survey meter results (in cpm), even for background count rates
  • Meter identification (model, serial number)
  • Follow-up action taken when contamination is found.

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Purchase, Repair and Calibration of Survey Meters

  • Call EHS for recommendations and information about purchasing a radiation survey meter. After a new meter arrives, call EHS to register the meter. Every survey meter must have a low-activity radioactive check source attached to it. Check sources are available from EHS.
  • EHS calibrates laboratory survey meters annually. When it is time for the annual calibration, EHS will notify each lab about the time and location of the calibration.
  • Call EHS whenever a survey meter is not functioning properly or needs to be repaired for any reason. EHS maintains repair and calibration records for each survey meter and can offer limited diagnostic and repair services.

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Inventory & Tracking

RITA, the Radioisotope Inventory & Tracking Application based in Princeton PRIME, is the main tool for inventorying and tracking your radioactive materials. 

Package Receipt

When a radioactive material package arrives at the Radioactive Receiving site, EHS reviews the shipping paper and the information on the vial and enters that information into RITA.  RITA assigns a unique Vial ID Number to the vial, and the EHS receiver puts labels with the Vial ID Number on the vial itself and on the shipping container.  The EHS receiver also prints out a Vial Use Log, places it in the package, and then delivers the package to the lab.

Using the Vial Use Log

An example of a Vial Use Log is shown in this photo:

The Vial Use Log

Whenever you withdraw material from a stock vial (the vial shipped by the vendor), you must use the Log to enter the date of withdrawal, your name, and the volume you removed.  There are other columns you may use, but only these first three columns are required to be completed.

Discarding Vials and Updating the Lab Inventory

When a vial is no longer useful and has been placed into a radioactive waste pail, the lab must notify EHS to remove the vial from the lab's inventory in RITA.  

  • In the Notes section of the Vial Use Log, note that the vial has been disposed of and the date of disposal.
  • Notify EHS that the vial has been discarded in one of the following ways:
    • Fax a copy of the Vial Use Log to EHS at 609-258-1804.
    • Return the Log via campus mail to EHS, 262 Alexander Street.
    • Log in to PRIME and use the EHS RITA module (Review User Inventory) to notify EHS.  Note:  Contact EHS to request access to RITA and to request instructions for using RITA.

Physical Inventory of Radioactive Materials

EHS asks each lab to physically review its inventory of stock vials periodically and to verify that the inventory as listed in RITA agrees with the actual inventory.  Instructions for doing this are included in the email from EHS that requests the physical inventory.

Radioactive Waste

5-Gallon Radioactive Waste Pail

This section includes information about the disposal of several different types of radioactive waste including solid waste, liquid waste, liquid scintillation counting wastes, mixed waste (waste that is both radioactive and chemically hazardous), and uranium and thorium wastes. 

Click on the links at the bottom of this page to see the specific procedures for each type of waste.

Preparing Waste Pails for Disposal

  1. Pull up the top of the yellow pail liner.  Close the neck of the bag and twist it.  Use the cable tie to close the bag securely.    
  2. Place the lid on the pail and twist the lid securely shut.
  3. Pail must not be overfilled – you must be able to seal the bag and close the pail. 
  4. Complete both halves of the the ID Tag.  Note that the Date on the tag is the date on which you deliver the pail to EHS. For long-lived wastes, you must enter the amount of radioactivity in the pail.  For short-lived waste, it is acceptable to check either the < 1 mCi or> 1 mCi boxes.

Removing Waste from Your Lab

  1. When the radioactive waste pails in your lab are filled or no longer needed, contact one of the waste collection staff listed in the Staff menu.  If your lab is located in Carl Icahn Laboratory, Guyot Hall, Lewis Thomas Laboratory, Moffett Laboratory or Schultz Laboratory, you will make an appointment to bring your waste pails to the Radioactive Waste Facility in Room 066, Moffett Laboratory.  If you work in any other building, you will make an appointment for EHS staff to pick up your waste pails. 
  2. Put your pails on a cart or carry them over.  Wear a lab coat and gloves.

Solid Radioactive Waste

Long-Lived Waste

For wastes with half-lives > 120 days. Example: solid waste contaminated with H-3 or C-14.

Solid wastes containing radioisotopes with half-lives greater than 120 days are collected in white 5-gallon polypropylene pails lined with heavy plastic yellow liners.

White 5-gallon pail for long-lived solid waste

Use this pail for solid wastes with half-lives > 120 days

Short-Lived Solid Waste (Decay-in-Storage Waste)

Solid wastes containing radioisotopes with half-lives of 120 days or less are collected in pails within laboratories and then transferred to a campus storage facility, known as the Decay-in-Storage (DIS) Facility. These wastes are held for a minimum of ten half-lives and then surveyed. If no detectable radioactivity is found, the waste is then disposed of as non-radioactive medical waste.

Decay-In-Storage Waste with Very Short Half-Lives (< 15 days)
Example: P-32

Solid wastes containing radioisotopes with half-lives < 15 days are collected in the lab in gray 5-gallon polypropylene pails lined with heavy plastic yellow liners.

Gray 5-gallon pail for P-32 waste

Use this pail for your P-32 solid waste.

Decay-In-Storage Waste with Moderately Short Half-Lives (between 15 - 120 days)
Example: P-33, S-35, I-125

Solid wastes containing radioisotopes with half-lives between 15 and120 days are collected in the lab in blue 5-gallon polypropylene pails lined with heavy plastic yellow liners.

Blue 5-gallon pail for solid wastes such as P-33, S-35 or I-125

Use this pail for P-33, S-35 and I-125 solid wastes.

Prohibitions

A red sharps box

Put your syringes, razor blades, pasteur pipettes and other sharps into a sharps box and then put the box into the radioactive waste pail!

  • No unprotected sharps
  • No liquids, except for droplet amounts and damp materials
  • No hazardous chemical wastes
  • No animal wastes
  • No contained sources (see the section below about contained source disposal)
  • No lead (such as lead pigs and lead shielding)

Radioactive Gels

Radioactive gels should be disposed of in the solid radioactive waste bins and not down the sink. They do not need to go in a secondary container in the solid waste bins.

Click here for Laboratory Radioactive Waste Disposal Procedures - Solid Waste

Disposing of Contained Sources

Examples of contained sources (plated and sealed sources)

In a contained source, the radioactivity is present in a form that is not easily dispersible due to its design characteristics.  For example, the radioactivity may be encapsulated in a welded capsule, embedded into a matrix or plated onto a surface.  Contact EHS prior to disposing of contained sources.  Special waste packaging and disposal arrangements may be necessary.

Liquid Radioactive Waste

Lab sink posted with Radioactive labeling

Liquid Waste

Liquid radioactive waste generated on campus may be disposed of through laboratory sinks if certain regulatory and University conditions are met. 

  • Sink Location
    You must use the pre-approved Radioactive Disposal sink in your lab.  As shown in the photo above, the sink will be clearly labeled with Radioactive labeling.
  • Solubility and pH
    The compounds you dispose of either be readily dispersible biological materials or must be aqueous or readily soluble in water. Refer to the list of Radioactive Compounds Approved for Drain Disposal.  If any of your compounds do not appear on the list, contact EHS for a solubility determination.  The pH of your waste must be 5-9.
  • Limiting Contamination
    Pour close and into the drain and run water for a minute after the disposal.
  • Recording & Reporting Disposals
    Every time you dispose of radioactive waste to the sink, you must record your disposal on the lab's Sink Disposal Log and estimate the amount of radioactivity released (see the Resource sidebar to download the form).  At the end of each calendar year, EHS will request that your lab report the total amount of radioactivity released per isotope for that calendar year.
  • Estimating the Amount of Radioactivity in Your Disposal
    You may consult with members of your own lab to estimate what percentage of the radioactivity is expected to end up in the liquid waste.  You may also contact EHS to collect samples of your liquid waste.  EHS will perform liquid scintillation counting of your samples and will provide you with radioactivity concentrations.  
  • Radioactive Gels
    Radioactive gels should be disposed of in the solid radioactive waste bins and not down the sink. They do not need to go in a secondary container in the solid waste bins.

Drain Disposal 

EHS maintains a list of radioactive compounds approved for drain disposal. Disposal of any material not on this list must be approved in writing by EHS. Questions: 609-258-5294 or ehs@princeton.edu

Compounds Approved for Drain Disposal PDF »

[Updated 2/19]

Liquid Scintillation Counting Wastes

A 5-gallon red plastic pail for liquid scintillation wastes

Use this red pail for liquid scintillation wastes.

All liquid scintillation vials, regardless of radioisotope, are collected in red 5-gallon polypropylene pails lined with heavy plastic yellow liners.

Restrictions

  • LSC solutions must have a flash point of 140°F or greater.  Most solutions described as eco-friendly or biodegradable are acceptable, but you are expected to read the product literature to verify that the flashpoint is at least 140°F.
  • Do not place any other waste materials (such as gloves, etc.) in the scintillation vial waste pails.
  • Be sure that the vials are tightly closed.

Mixed Wastes

Mixed wastes are radioactive wastes which also contain hazardous waste components regulated under RCRA (the federal Resource Conservation and Recovery Act) regulations.  It may not be easy to dispose of mixed wastes, and often we must establish special collection and storage procedures that are specific to your protocols.  Contact EHS before generating mixed wastes.  

In the laboratory setting the type of mixed wastes most likely to be generated include:

  • contaminated lead
  • certain organic solvents such as chloroform, phenol, toluene and xylene.

If you are not sure whether your wastes are mixed wastes, i.e., containing both radioactive and hazardous components, contact EHS to make the determination.

Uranium and Thorium Wastes

Do not dispose of any uranium or thorium compounds as regular trash or as hazardous chemical waste. In general, all uranium and thorium wastes, regardless of how the uranium or thorium was purchased, must be disposed of as radioactive waste. Contact the Radiation Safety Officer to discuss disposal options and to make disposal arrangements.

Radioactive Sewer Release Report

Isotope #1
μCi
Isotope #2
μCi
Isotope #3
μCi
Isotope #4
μCi
Isotope #5
μCi
Isotope #6
μCi
Isotope #7
μCi
Isotope #8
μCi
Please send all calendar year sewer release paper copies to EHS at 262 Alexander St.

Spills & Incidents

Is It an Emergency If It Involves Radioactive Materials?

Problems involving radioactive materials, such as spills or personal contamination, do not typically create emergencies. Generally such incidents can be readily handled with laboratory or other University resources instead of calling non-University emergency responders.  A situation involving radioactive materials is only an emergency if it also involves fire, explosion or serious injury.


Who To Call

For skin or clothing contamination or major spills or EHS advice

  1. During normal working hours, call EHS at 8-5294
  2. Outside normal working hours, call EHS at 8-5294. You will hear a menu directing you to either leave a message or speak to a safety officer directly. Note: The immediate contact option should be used for radioactive materials incidents only. 

For an emergency
Remember that an emergency only exists if there’s fire, explosion or the risk of serious injury.

  1. Call Public Safety first. Call 911 from a campus phone or call 609-258-3333.
  2. During normal working hours, also call EHS at 8-5294
  3. Also contact any Laboratory or Departmental Emergency contacts listed on the Emergency Information poster found on or near the entrance to the laboratory.

What To Do

Skin Contamination

  1. Call EHS immediately. EHS must be notified any time contamination is found on your skin, even if you’re able to completely decontaminate your skin. The RSO will respond to any incident of skin contamination, no matter what time the incident has occurred.
  2. Make a note of the original meter reading so that the Radiation Safety Officer can estimate the radiation dose to your skin.
  3. Wash your skin gently under room-temperature water for about 2 minutes, using gentle soap or detergent. Do not use abrasives or alkaline soaps.
  4. Resurvey your skin to see if the contamination has been removed.

Contamination on Any Clothing Other than Lab Coats

Call EHS immediately. EHS must be notified any time contamination is found on your clothing. The RSO will respond to any incident of clothing contamination, no matter what time the incident has occurred.

Lab Coat Contamination

  • Call EHS if you are concerned that contamination may have soaked through the fabric of the lab coat or if the count rate is unusually high.
  • For short-lived isotopes (P-32, P-33, S-35, I-125):
    • Mark the location of the contamination.
    • Place the coat in a plastic bag and securely close it.
    • Label the bag with the current date, the isotope and the count rate. Put Caution Radioactive Material labeling on the bag.
  • For long-lived isotopes (H-3, C-14), consult with the RSO to decide whether to attempt to decontaminate the coat or to dispose of it.

Spills and Contamination of Surfaces

We define two types of contamination incidents, either a minor spill or a major spill. There will be many incidents that don’t obviously fall into one category or the other. Call EHS if you are uncertain whether your incident is a Minor Spill.

A Minor Spill is any incident that involves all of the following criteria:

  • Less than 10 µCi of radioactivity has been spilled.
  • Contamination is limited to a small area of no more than 2-3 square feet.
  • There is no clothing or skin contamination.
  • You are certain that you can manage the surveys and decontamination on your own without assistance.

Handling a Minor Spill

Minor Spill or Contamination

Spill Decontamination Procedure

Supplies: a lab coat, sturdy disposable gloves, shoe covers (if appropriate), paper towels, decon solution, a rad waste container, and a survey meter.

Decon Solution:  For most isotopes (H-3, C-14, P-32, P-33, S-35, etc.), lab detergent, commercial products such as Count-Off, or mild acids such as acetic acid, may be used as decon solutions.  For I-125 contamination, do not use hot water, acids or acidic detergents, because volatile iodine may be produced.  A basic decon solution such as Count-Off or Dekasol may be used.

  1. Get supplies ready before cleanup.
  2. Use a survey meter or a wipe survey to carefully define the extent of the contaminated area.
  3. Mark the contaminated area with tape or other marking.
  4. Start the clean-up at the edge of the contaminated area and work inward.
  5. Clean wet spills or contamination using absorbent paper towels.
  6. Change paper towels frequently to avoid smearing contamination around.
  7. Change gloves frequently and watch out for rips and tears.
  8. Survey all personnel involved in the clean-up.  survey shoes as wella s hands and lab coats.
  9. Record the clean-up and personnel surveys in the lab survey log.
  10. Call EHS for assistance and information.

Dealing with a Major Spill

A Major Spill is any incident that is not a Minor Spill and includes the discovery of contamination in unexpected places or in many places.  As you read through these steps, keep in mind that EHS responders will arrive soon to help manage the situation.

  1. Notification:  Notify everyone in the lab or possibly in the vicinity of the lab, if it seems warranted.  Ask someone to immediately call EHS or Public Safety (see Who To Call).
  2. Personnel Protection: Assess your own condition and determine whether you need to decontaminate yourself or to remove contaminated clothing.
  3. Control Access & Limit the Spread of Contamination:  Block off the area so that bystanders don't enter.  Assemble people who were in the lab at the time of the incident in a place near enough to the contaminated area to minimize the spread of contamination but far enough away to prevent the continued spread of contamination.
  4. Decontamination:  The effort to decontaminate the area is the responsibility of the Authorized User and lab staff, although EHS will plan the effort and will assist you with the clean-up.

Missing Radioactive Materials

The loss or theft of radioactive materials must be reported to EHS immediately.  If you have discovered that a vial of radioactive material is missing or can't be accounted for, take a few minutes to try to locate it, but notify EHS before the end of the business day.  EHS is required to notify the New Jersey Department of Environmental Protection when a quantity of radioactive material is missing that exceeds the reportable limits.

Shipping & Moving Radioactive Materials

Off Campus Shipment

The shipping of radioactive materials is regulated domestically as “hazardous materials” by the U.S. Department of Transportation and internationally as “dangerous goods” by the International Air Transportation Association (IATA).  EHS will work with you to ensure that your shipment complies with national and international regulatory requirements.   

Contact EHS as far ahead of time as possible by filling out the Hazardous Materials Shipment Request Form completely.   EHS will contact you to work out the details of the shipment. 

On Campus Transfers of Radioactive Materials

Never transport/move radioactive materials, even to an adjacent building, without first contacting EHS.  You may need specific packaging and labelling and occasionally shipping papers.

Pregnancy in a Radioisotope Lab

If you are pregnant and work with radioactive materials or near areas where radioactive materials are used, you may be concerned about the amount of radiation dose the baby might receive and whether radiation exposure presents a prenatal hazard. You are encouraged to contact the Radiation Safety Officer (RSO). The RSO will handle your inquiries confidentially, if you request it.

The RSO can:

  • provide you with informational material about the risks of prenatal radiation exposure
  • assess your potential for radiation exposure
  • provide you with isotope-specific guidelines for minimizing radiation exposure
  • provide an opportunity for you to submit a Declaration of Pregnancy
  • provide radiation monitoring badges to measure fetal dose during your pregnancy (if you have submitted a Declaration of Pregnancy).

What is a Declaration of Pregnancy and a Declared Pregnant Worker?

The New Jersey Department of Environmental Protection (NJDEP) has established regulations that limit fetal radiation dose under certain conditions.

  • The fetal dose regulations apply only if you have voluntarily informed Princeton University, in writing, of your pregnancy and the estimated date of conception. This notice is called a Declaration of Pregnancy. If you submit a notice, you are known as a Declared Pregnant Worker. You are not required to submit a Declaration of Pregnancy, and you may withdraw your Declaration at any time.
  • The dose to the fetus resulting from occupational exposure of a declared pregnant woman may not exceed 500 millirems for the entire pregnancy.
  • If you perform work that has a high potential for the fetal dose to exceed 500 millirems, it might be necessary to modify your duties.  Fortunately, for the type of radiation work performed at Princeton University, it is rarely necessary to recommend reassignment or changes to job duties.
  • If you choose not to submit a written Declaration of Pregnancy, then your dose continues to be controlled under the normal dose limits for radiation workers (the whole body dose limit is 5000 millirems per year).

If you submit a Declaration of Pregnancy, EHS will provide you with a radiation monitoring badge, exchanged on a monthly basis, to measure the fetal dose.
 

Radiation Training

Even if you’ve attended radiation safety training at other institutions, you’re required to complete Princeton University training. If you’re not sure what training you should complete, contact the RSO.

The type of training you need to complete depends on which form of radioactivity is used in your lab.  

  • If the radioactivity is present in a form that is easily dispersible, for example, liquids, powders and gases, it is an Open Source. Most biological and chemical applications use open sources.
  • If the radioactivity is present in a form that is not easily dispersible due to its design characteristics, it is a Contained Source.   Typically the radioactivity in a Contained Source is encapsulated in a welded capsule, embedded into a matrix or plated onto a surface.
  • Special training is available for people who work with Uranium or Thorium compounds, such as uranyl acetate or thorium nitrate.

Lab supervisors must ensure members of their labs are trained in the safe and proper practices for the procedures and materials used. A Lab Safety Orientation Checklist should be completed to ensure proper training level.


Open Source Labs

If You Have No Plans to Use Radioactivity

You must complete Radiation Safety Awareness Training for Non-Radioisotope Users, which is provided online. Refresher training is not required.

Go to the Employee Learning Center and log in.  Click on Training by Department  > Environmental Health & Safety. On the Environmental Health & Safety tab, click on Radiation Safety and find the listing for Radiation Safety Awareness Training for Non-Radioisotope Users.

If You Plan to Work with Radioactive Materials

Initial Training: You must complete the online Radiation Basics modules and test, and you must attend the two-hour Radioactive Materials Safety Class.

For the Radiation Basics Modules, go to the Employee Learning Center and log in.  Click on Training by Department  > Environmental Health & Safety. On the Environmental Health & Safety tab, click on Radiation Safety and find the listing for Radiation Basics Modules for Open Source Users.  After you complete the modules, you can register for an upcoming Radioactive Materials Safety Class.

Refresher Training:  You must attend annual refresher training annually. Refresher training is presented at a meeting for your lab and typically includes a brief review of problems noted in the labs, inspection results, and incident response procedures.  You can see the refresher training presentations for the most recent years here:


Contained Source Labs

Only people actually using radioactive sources must complete training. If you plan to work with contained sources, you must complete:

    Initial Training: The training is completely online. Go to the Employee Learning Center and log in.  Click on Training by Department  > Environmental Health & Safety. On the Environmental Health & Safety tab, click on Radiation Safety and find the listing for Radiation Safety Training for Contained Source Users

    Refresher Training:  You must complete annual refresher training every three years. Go to the Employee Learning Center and log in.  Click on Training by Department  > Environmental Health & Safety. On the Environmental Health & Safety tab, click on Radiation Safety and find the listing for Refresher - Radiation Safety Training for Contained Source Users


    Uranium and Thorium Compounds

    Only people actually using uranium and thorium compounds must complete the online training module, Radiation Safety Training for Users of Uranium and Thorium Users. 

    Go to the Employee Learning Center and log in.  Click on Training by Department  > Environmental Health & Safety. On the Environmental Health & Safety tab, click on Radiation Safety and find the listing for Radiation Safety Training for Uranium and Thorium Users

    Radiation Safety Manual

    This page contains the official text of the Princeton University Radiation Safety Manual.  The Manual is provided to the NJ Department of Environmental Protection as part of the University's application for a license to possess and use radioactive materials.  It is also provided to radioactive materials users during radiation safety training.  The Manual is presented here because it is an important part of the documentation of our radiation safety program.  Some of the information contained in the Manual is presented elsewhere on the Radiation Safety pages, but generally the Manual provides greater detail. To request a copy of the Manual, contact the Radiation Safety Officer.


    Preface

    The Princeton University Radiation Safety Manual is a handbook of procedures and useful information for the radiation worker who uses either radioactive materials or radiation-producing machines in a laboratory setting at Princeton University. The Manual also reflects the requirements of relevant federal and state regulations. The Manual supplements but does not replace the required radiation safety training which all radiation workers must receive.


    Introduction: Radiation Safety at Princeton University

    The radiation safety program at Princeton University combines the best efforts of its Radiation Safety Committee, its radiation safety staff and all of its employees, students and visitors to ensure the safe use of radioactive materials.

    Princeton University is licensed by the New Jersey Department of Environmental Protection (NJDEP) to possess and use many different radioisotopes. This license has been issued by NJDEP only because the University has established policies and procedures designed to ensure the accountability of radioactive materials and which will minimize the exposure of people to radioactive materials.

    There are four key components to Princeton University’s radiation safety program:

    The roles and responsibilities of each are described below:

    The Radiation Safety Committee (RSC)

    The Committee

    • oversees the radiation safety program
    • authorizes the use of radioactive materials
    • reviews incidents involving radioactive materials
    • sets policies for the use of sources of radiation
    • gives general supervision to the implementation of those policies.

    The Environmental Health and Safety Office

    The day-to-day operation of the radiation safety program is managed within the Environmental Health & Safety Office (EHS) by the University’s Radiation Safety Officer (RSO). The RSO and the Radiation Safety staff are available to advise Authorized Users and radiation workers on radiation safety and regulatory compliance issues and to provide the following services:

    • training
    • personal monitoring and dosimetry services
    • bioassay
    • pregnancy counseling
    • laboratory radiation surveys
    • incident, spill and contamination management
    • radioactive waste management

    Appendix D lists the names, phone numbers, e-mail addresses and primary areas of responsibility of the Radiation Safety staff.

    The Authorized User

    Authorized Users are faculty members or senior staff members who have been approved by the Radiation Safety Committee to use radioactive materials under specific conditions. An Authorized User is granted approval to possess and use specific isotopes only for the uses described in the authorization application and is issued a possession limit for each of those isotopes. Any person using radioactive materials at Princeton University is either an Authorized User or is a radiation worker using radioactive materials under an Authorized User’s supervision. Each Authorized User is responsible for:

    • the health and safety of anyone using or affected by the use of radioactive materials under his or her direction or supervision.
    • personally attending initial and annual refresher training and ensuring that his/her employees, staff and visitors receive appropriate training.
    • ensuring that his/her employees, staff and visitors comply with relevant regulations, policies and procedures.

    The Radiation Worker

    A radiation worker is anyone who uses radioactive materials or radiation-producing machines. The radiation worker’s thorough training, compliance with regulations and procedures, careful work habits and respect for the health and safety of fellow workers are an integral part of the radiation safety program. A radiation worker’s responsibilities include the following:

    • Complete the initial radiation safety training program and, for open source users, attend annual refresher radiation safety training offered by EHS.
    • Be familiar with the isotopes in use; know their radiological, physical and chemical properties, methods of detection, the types of hazards presented by each one, and the specific precautions and handling requirements for each isotope.
    • Be familiar with all the relevant procedures of the radiation safety program, including isotope purchasing and waste disposal procedures.
    • Know how to properly use the appropriate radiation survey meter.
    • Know how to use radiation monitoring badges and exchange them promptly at the end of the monthly or quarterly wear period.
    • Maintain appropriate inventory, disposal and survey records.
    • Secure radioactive materials by making sure that radioactive materials are locked away or are under immediate supervision within the laboratory.
    • Inform coworkers and visitors to the work area about the presence of radioactive materials and of any precautions they should take.
    • Know who to call in any incident involving sources of radiation and how to handle spills and personal contamination.

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    Section 1: Spills & Incidents

    Who to Notify

    What to Do

    An accident may happen to even the most careful of workers, and any worker may be called upon to assist in the case of a spill, a contamination incident, or an emergency. Be prepared and know how to respond before an incident happens. The following procedures provide an overview of who to notify and how to respond to several different types of incidents. Emergency Response Guidelines books which list incident contact phone numbers and procedures are posted near a telephone in every lab.

    NOTE: Problems involving radioactive materials, such as spills or personal contamination, do not typically create emergencies. Generally such incidents can be readily handled with laboratory or other University resources instead of calling non-University emergency responders. A situation involving radioactive materials is only an emergency if it also involves fire, explosion or serious injury.

    Who To Notify

    Incident

    An incident can be readily handled with laboratory or other University resources and may include a spill of radioactive materials, an incident of personal contamination or a possible exposure to an x-ray source.

    • During normal working hours, call Environmental Health & Safety (EHS) at 609-258-5294, or
    • Outside normal working hours, call EHS at 609-258-5294. You will hear a menu directing you to either leave a message or speak to a safety officer directly. Note: The immediate contact option should be used for radioactive materials incidents only. 

    Emergency

    In the event of a fire, explosion or serious injury:

    • Call Public Safety at 911 anytime (use a campus phone to dial 911 or, if using a cell phone, dial 609-258-3333).
    • During normal working hours, also call EHS at 609-258-5294.
    • Also contact any Laboratory or Departmental Emergency contacts listed on the Emergency Information poster found on or near the entrance to the laboratory.

    Reporting Requirements

    You must notify immediately EHS if:

    • You have a spill exceeding 10 µCi.
    • You have widespread contamination.
    • You have contamination on skin or clothing (other than a lab coat) or shoes.

    What to Do

    When a Spill Occurs or Contamination is Found

    Assess the extent of the contamination or the spill and ask:

    • Is this a minor spill or contamination incident?  Can I realistically handle this incident without help and without undue risk to me?  Do I have the resources I need to deal with this incident?
      If so, see Table 1 below.
    • Is contamination widespread?  Does this involve more than 10 µCi? Has a spill caused radioactive material to splatter?   Do I need help to manage and clean up this incident?
      If so, see Table 2 below.

    Table 1: Minor Spill or Contamination

    Spill Decontamination Procedure

    Supplies: a lab coat, sturdy disposable gloves, shoe covers (if appropriate), paper towels, decon solution, a rad waste container, and a survey meter.

    Decon Solution:  For most isotopes (H-3, C-14, P-32, P-33, S-35, etc.), lab detergent, commercial products such as Count-Off, or mild acids such as acetic acid, may be used as decon solutions.  For I-125 contamination, do not use hot water, acids or acidic detergents, because volatile iodine may be produced.  A basic decon solution such as Count-Off or Dekasol may be used.

    1. Get supplies ready before cleanup.
    2. Use a survey meter or a wipe survey to carefully define the extent of the contaminated area.
    3. Mark the contaminated area with tape or other marking.
    4. Start the clean-up at the edge of the contaminated area and work inward.
    5. Clean wet spills or contamination using absorbent paper towels.
    6. Change paper towels frequently to avoid smearing contamination around.
    7. Change gloves frequently and watch out for rips and tears.
    8. Survey all personnel involved in the clean-up.  survey shoes as wella s hands and lab coats.
    9. Record the clean-up and personnel surveys in the lab survey log.
    10. Call EHS for assistance and information.
    Table 2: Major Spill or Contamination
    1. Notify all personnel within the lab and in the vicinity of the lab, as appropriate.
    2. Notify EHS and deprtmental safety contacts.
    3. Assess the need for personnel protection measures such as removing contaminated clothing or cleaning contaminated skin.
    4. Block off the area.  Keep bystanders out of the area.  Assemble persons who were in the lab at the time of the incident.  Keep them close enough to the contaminated area to limit the spread of contamination but far enough away that no one is at risk of getting further contaminated.
    5. Do not track contamination beyond the area.  Remove contaminated shoes and put on clean shoes or put protective covers over shoes before leaving the contaminated area.
    6. Survey everyone and anything leaving the contaminated area.
    7. Decontamination is the responsibility of the Authorized User's lab personnel.  Clean-up should be performed under the supervision of EHS radiation safety staff.

    For Skin and Body Contamination

    1. Notify EHS immediately whenever any case of skin or body contamination occurs.
    2. Note the original survey meter reading, the location of the contaminated area and the time of the contamination was discovered. EHS will use this information to calculate dose.
    3. Wash skin using mild soap and warm water for 2-3 minutes. Do not abrade skin or use hot water.
    4. Measure and record the count rate after the initial attempt at decontamination. Survey and repeat decontamination until the count rate cannot be reduced any further.
    5. If the skin becomes irritated, discontinue decontamination.
    6. When decontamination efforts are not immediately successful, often a substantial reduction in count rate is achieved during the next 24 hours with periodic washings with soap and water, combined with normal flaking of the skin.

    A Serious Injury with Radioactive Contamination

    Serious injury and life-or-death situations always take priority over radiological concerns. In all cases of physical injury, even minor injuries, medical attention and hospitalization take precedence over contamination concerns. There are no radiation sources at the University that produce contamination and radiation exposure risks large enough to prevent first aid from being given.

    1. Follow the Fire, Explosion & Serious Injury notification procedure. Public Safety responders are trained to provide first aid.
    2. If possible, have someone meet emergency response personnel and escort them to the accident scene.
    3. Remove contaminated items and clothing from the victim only if these actions will cause no further harm.
    4. If time permits, attempt to provide an uncontaminated pathway for the emergency crew.
    5. Have someone who can provide useful additional information accompany the victim to the emergency room.

    Possible Overexposure to Sources of Radiation

    The most likely scenario for a serious overexposure to radiation involves exposure to the primary beam of an x-ray diffractometer or to a high activity sealed source. In any case, notify EHS, who will provide additional instructions, based on the exposure conditions.

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    Section 2: Using Radioisotopes Safely

    In some cases the practices described below are required by regulation or by license conditions but in all cases these practices represent good laboratory practices which will promote the safe use of radioactive materials.

    Protective Clothing

    Lab accidents often involve spills or splashes which can readily contaminate exposed wrists, legs and feet. For any work with an open radioactive source, wear:

    • gloves (the longest length available)
    • a full-length lab coat (worn closed with sleeves rolled down)
    • close-toed shoes. Do NOT wear sandals or other open-toed shoes while working with radioactivity

    It is strongly recommended that you wear safety glasses for any procedure, but it is essential that you war safety glasses whenever there is a potential for the build-up of pressure.

    Keep an extra set of clothing and shoes in the lab in the event that clothing becomes contaminated.

    Avoid using petroleum-based hand creams when wearing gloves because petroleum-based hand creams may increase glove permeability.

    Food and Beverages

    • Do not eat, drink or smoke in any room in which open sources of radioactive materials are used.
    • Do not store food, beverages, or medicines in refrigerators, freezers or coldrooms where open sources of radioactive materials are used or stored.
    • Do not store food, beverages, medicines, cosmetics, coffee cups, eating utensils, etc. on open surfaces near lab benches where contamination can be
      readily spread.

    Mouth Pipetting

    Never mouth pipet radioactive solutions.

    Security

    • Lock radioactive stock materials and sealed sources in a secured container or a secured storage area when not in use. A stock material is radioactive material as provided by the vendor and does not include material withdrawn from the original stock for experimental use.
    • Do not leave radioactive materials unsecured in an unattended lab, even for a short time, unless the lab is locked.
    • Supervise visitors to the lab.
    • When visitors who are not accompanied by authorized lab personnel enter the lab, find out who they are and why they are there.
    • If you discover that radioactive material is missing or lost and cannot be accounted for, notify EHS no later than the next business day.

    Signs and Labels

    For the radioisotopes commonly used at Princeton University, labeling of rooms and containers is mandatory under the following conditions:

    Radioisotope

    Activity for Which Labeling

    is Required (uCi)

    H-3 1000
    C-14 100
    P-32 10
    P-33 100
    S-35 100
    Ca-45 100
    Cr-51 1000
    Fe-59 10
    Zn-65 10
    I-125 1
    U-238 100
    • Labeling Contaminated items and containers of radioactive material is an important tool for contamination control and is a courtesy to other laboratory personnel.
    • Any container of radioactive material, any room or piece of equipment in which radioactive material is stored and any contaminated area or item,regardless of the level of radioactivity, should be labeled as Radioactive.
    • Radioactive Material tape is available from the Molecular Biology Department and Chemistry Department stockrooms.

    Fume Hoods and Biosafety Cabinets

    Work with certain radioactive materials, such as volatile I-125 or millicurie amounts of S-35 methionine/cysteine, must be performed in a designated radioactive materials (RAM) fume hood.

    • An RAM hood must be posted with an Environmental Health & Safety (EHS) RAM sticker, and a Class A or a Class B hood. For radioiodine work, a RAM hood must be a Class A hood with an average face velocity of at least 100 lfpm. The hood class is shown on the EHS hood survey sticker.
    • To verify that the hood is functioning properly, compare the current reading for the hood’s continuous flow monitoring device (e.g., magnehelic) with the expected reading shown on the EHS hood survey sticker.
    • Biological safety cabinets (or laminar flow hoods) may not be suitable for radioisotope work, since the air from the cabinet may be exhausted back to the room. Consult with EHS before performing work with volatile radioactive materials in a biological safety cabinet.

    Biological and Chemical Hazards

    In addition to radiation hazards, some experimental protocols may pose biological and chemical hazards as well. Be familiar with all the risks associated with an experiment, follow any necessary precautions, and know the proper disposal techniques for the resulting wastes.

    Keeping Radiation Exposure ALARA

    The acronym ALARA, which stands for As Low As Reasonably Achievable, means that radiation workers should make every reasonable effort to keep radiation exposures as far below regulatory dose limits as practical. Adhering to the following practices can help keep radiation doses ALARA.

    • Be familiar with the properties of the radioisotope to be used and with any precautions and concerns specific to that radioisotope and material. (See Appendix B for detailed information about the radioisotopes most commonly used at the University).
    • Unfamiliar radioisotope procedures should be rehearsed before radioactive material is actually used.
    • Wear protective clothing.
    • Wear radiation monitor badges when appropriate.
    • Have all the necessary materials and equipment available and ready at the start of a procedure.
    • For those radioisotopes with significant external radiation levels, use remote handling tools, such as tongs, to limit direct handling of stock and sample vials.
    • Survey frequently and extensively. Don't assume that contamination will only be found on the bench top.
    • Clean up contamination in the work area promptly.
    • Change gloves and lab coats as they become contaminated.
    • Work in a hood during procedures using volatile materials such as I-125 or millicurie amounts of S-35 methionine/cysteine.
    • Cover radioactive waste cans at all times and store waste cans away from areas in which people spend substantial amounts of time. Provide shielding for waste cans with significant external radiation levels.
    • Do not store contaminated materials, including gels, at any desk area.
    • Survey yourself and your clothing when radioisotope work is finished and before leaving the lab.

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    Section 3: Acquiring Radioactive Materials

    Princeton University must track and control all radioactive materials received to ensure that the University’s possession limits for radioactive materials (under the license issued by the state of New Jersey) are not exceeded. Therefore, the ordering and acquisition of radioisotopes must follow very specific rules and procedures. There are a few important rules for the purchase and acquisition of radioactive materials that laboratory workers must keep in mind:

    Rule #1: Never place orders for radioactive materials directly with a vendor. All radioisotope orders must be placed in PRIME and must be coded as Radioactive. Replacements for incorrect orders or unusable shipments must be negotiated by the Purchasing Department.

    Rule #2: Each laboratory using radioactive materials has been issued an Authorization for each isotope. This Authorization spells out the lab’s possession limit for that isotope and the conditions of use. EHS will not approve an order if the order will cause the lab’s Authorization limit to be exceeded.

    Ordering Procedures

    Note:  The procedures provided in the Manual for ordering radioactive materials no longer apply since the University's transition to Princeton PRIME.  Click here for updated procedures.

    Free Vendor Samples and Samples from Other Institutions

    Any person who plans to acquire radioactive material as a gift, loan or transfer from a vendor, another institution or company must contact EHS before the material is shipped to the University. Just as with regular radioisotope orders, EHS must approve any shipments before they are shipped. In addition, EHS arranges the shipment with the other institution and sends a copy of our radioactive materials license. Failure to notify EHS in advance about the shipment of radioactive materials may cause a lab’s authorization to be suspended or revoked.

    Loans or Other Transfers of Radioactive Material

    Transfers of radioactive material between Princeton University labs are permitted under the following conditions:

    • Transfers of sealed sources or plated sources are not permitted without written authorization from EHS.
    • The lab transferring the material is responsible for ensuring that the recipient lab is authorized to possess the radioisotope in question.
    • Transfers of open source radioactive material in amounts of 100 µCi or more must be reported to EHS no later than the next business day.

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    Section 4: Package Receipt & Inventory

    Receiving a Package

    1. All radioactive material packages are delivered to a central radioisotope receiving area. Environmental Health & Safety (EHS) staff open the package, check the packaging for contamination, inspect the packing list and vial label to verify that the vial contains the contains the material actually ordered, and enter the shipment into the University’s radioisotope inventory and tracking database (RITA). RITA assigns a unique ID Number to each vial or source, and EHS staff place a label bearing the ID Number on the vial or source.
    2. When EHS has finished its survey of the package and has entered it into the inventory database, the vial or source is repackaged in its original package. The package is taped securely closed, and an EHS Package Release Label is placed on the package. In addition, EHS supplies a Vial Use Log or Sealed Source Inventory Log with each vial or source of radioactive material.
    3. Although EHS staff delivers packages to each department, the respective departments are responsible for establishing departmental procedures for transferring packages to laboratory personnel.
    4. When a package is delivered to the lab or picked up from the department’s receiving room, the person who accepts the package is asked to sign a receipt log (in some departments only designated lab representatives may sign for radioisotope packages). Before signing for a package, examine the packing list and the labels on the package to verify that this package is the same package described on the receipt log.
    5. Although EHS staff checks the vial and packing list against the requisition to look for errors in the shipment, recheck the packing list to verify that the package contains the expected material.
    6. After signing for any package, make sure that the package is immediately placed in a secured location.
    7. After signing for a package, promptly notify the person who ordered the material or who will use it that the package has arrived.

    Opening Packages

    The precautions described below are necessary because packages are occasionally delivered with the wrong materials, may contain highly contaminated inner vials, or vials may unintentionally become pressurized during transport.

    1. Wear protective clothing and open the stock vial in a fume hood when practical.
    2. Verify that the stock vial contains the material you ordered in the amount you ordered. If there are any discrepancies, call EHS and the Purchasing Office immediately.
    3. Before the package is delivered to the laboratory, EHS surveys the packing materials or packing containers for contamination. However, you should wipe test the inner container or stock vial to check for gross contamination (See Section 5 for information on performing a survey).
    4. Extensive contamination on the inner vial should be reported immediately to EHS.

    Discarding Packaging Materials

    1. Survey any box or packaging material to be sure it is not contaminated before placing it out for the regular trash or sending it for recycling.
    2. Completely mark out, tape over, or remove all radioactive material labels on any empty packaging before placing the package out for pickup as non-radioactive trash. This is a specific NJDEP regulatory requirement.

    Inventory Control

    All stock vials, sealed sources and plated sources are assigned a unique identification number through the Princeton University radioisotope inventory and tracking database, known as RITA. Sources are tracked in RITA through the use of this ID number. In order to maintain adequate inventory control over the use and disposal of radioactive materials at the University, the following procedures have been established. EHS provides the laboratory with detailed written procedures for all phases of the inventory control and tracking process.

    • Record all withdrawals of material from a stock vial on the Vial Use Log.
    • When a stock vial is placed into radioactive waste, mail the Vial Use Log for that vial back to EHS. When EHS receives the Vial Use Log, EHS deletes the stock vial in RITA from the Authorized User’s active inventory.
    • An Authorized User’s active inventory can be viewed online through PeopleSoft. RITA performs decay calculations so that lab members can see the amount of radioactivity available, corrected for decay. Detailed procedures for using RITA are found in the Laboratory User’s Guide to RITA, available from EHS.
    • Once each quarter, labs must perform a physical inventory of radioactive materials stored in the lab, compare the actual inventory to the online inventory in RITA and report any discrepancies to EHS.
    • The procedure for handling transfers of radioactive material is described in Section 3.
    • If a lab discovers that radioactive material is missing or lost and can not be accounted for, EHS must be notified no later than the next business day.

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    Section 5: Surveys & Contamination Control

    Frequent surveys performed by knowledgeable laboratory personnel are the main line of defense to detect spills and to prevent the spread of contamination within and beyond the laboratory. This section summarizes the requirements for performing surveys. See Appendix A for detailed information about the types of contamination surveys, how to use a survey meter, how to perform a survey using a survey meter and how to perform a wipe test.

    Survey Instrumentation

    Table 5.1 summarizes the instrumentation and method of choice for the isotopes most commonly used at Princeton University.

    Performing a Meter Survey

    Appendix A provides detailed instructions on the use of a survey meter and how to perform a survey. The following list is a brief survey checklist:

    • Perform a battery test
    • Perform an operational check the first time you use the meter each day
    • Check meter background. Meter background should be < 100 counts per minute (cpm) for a G-M meter and < 300 cpm for a sodium iodide (NaI) scintillation meter.
    • Perform the survey
    • Decontaminate or label contaminated areas and items.
    • Document survey results in your personal survey log or in the lab survey log.

    Defining Contamination

    If an item or area with a sustained count rate of three times background or more is found, the item or area should be considered to be contaminated.

    When to Survey

    Laboratory personnel must conduct individual work area surveys (surveys of floors, workbenches, handles, experimental equipment, etc.) and personal surveys (surveys of one’s person and clothing) under the following conditions:

    • at the end of an experimental procedure;
    • at the end of each day for multi-day procedures;
    • frequently during the manipulation of millicurie quantities of open sources;
    • following the opening of radioactive material packages;
    • following withdrawals from stock vials containing more than 1 mCi;
    • prior to exiting the laboratory (for personal surveys)

    Where to Survey

    Survey areas where splashes or spills may have occurred and areas where a person could unknowingly transfer contamination. Typical survey locations include:

    • Bench tops, including the edges
    • Fume hoods (aprons, sashes, sash handles)
    • Beta shields
    • Refrigerator and freezer door handles
    • Sinks designated for radioactive material disposal (sink basin, surrounding bench, faucet handles)
    • Floors: at working areas, laboratory entrances, waste containers, fume hoods
    • Communal equipment, such as pipettors, timers, incubators, centrifuges, water baths, etc.
    • Non-radioactive trash (to ensure that contaminated waste is not disposed of as regular trash)
    • Clean areas (offices, desks, doorknobs, phones, computers)

    When to Document Surveys

    Document the survey results:

    • when radioactivity in amounts of 250 µCi or more have been handled,
    • whenever contamination is discovered, regardless of the amount used, and
    • to show follow-up actions, whenever contamination has been cleaned up.

    How to Document Surveys

    Record survey results in a personal survey log or in the laboratory survey log. Appendix A contains a copy of a blank survey log page. Each log entry should contain the following information:

    • Name of person performing the survey
    • Date of survey
    • Brief description of the area surveyed
    • Survey meter results (in cpm), even for background count rates
    • Meter identification (model, serial number)
    • Follow-up action taken when contamination is found.

    When to Report Contamination

    • Skin contamination, regardless of level of contamination, must always be immediately reported to EHS.
    • Uncontained spills (e.g., spills outside of contained areas on the work bench or hood) in excess of 10 µCi must be promptly reported to EHS.
    • Widespread contamination in any amount should be promptly reported to EHS. Contamination is considered to be widespread if it is found in several locations which are not normally expected to be contaminated (e.g., on floors and handles, in non-radioisotope areas, etc.).

    Purchase, Repair and Calibration of Survey Meters

    Call EHS for recommendations and information about purchasing a radiation survey meter. After a new meter arrives, call EHS to register the meter. Every survey meter must have a check source attached to it. Check sources are available from EHS.

    EHS performs a periodic electronic calibration of laboratory survey meters. Meters must be calibrated at least annually.

    Call EHS whenever a survey meter is not functioning properly or needs to be repaired for any reason. EHS maintains repair and calibration records for each survey meter and can offer limited diagnostic and repair services.

    Table 5.1

    Survey Instrumentation Guide

    Radioisotope Acceptable Survey Method Comments
    H-3 LSC There are no other acceptable survey methods
    C-14 G-M or LSC LSC is most sensitive; G-M detects moderate to high levels of contamination; do not cover G-M with parafilm
    P-32 G-M or LSC G-M detects low levels of contamination
    P-33 G-M or LSC LSC is most sensitive; G-M detects moderate to high levels of contamination; do not cover G-M with parafilm
    S-35 G-M or LSC LSC is most sensitive; G-M detects moderate to high levels of contamination; do not cover G-M with parafilm.
    Cr-51 NaI, g, or LSC  
    Zn-65 G-M or g  
    I-125 NaI, g, or LSC  
    U-238 G-M or LSC  

    Table Key:
    G-M = Survey meter with a Geiger-Muller detector
    LSC = liquid scintillation counting
    NaI = survey meter with a thin crystal sodium iodide detector
    g = gamma counter

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    Section 6: Dose Limits & Personal Monitoring

    Annual Radiation Dose Limits

    Each worker who is monitored for external or internal radiation exposure at the University is notified about the doses he or she receives. For example, a worker who is notified that that he or she received a whole body dose of 50 millirems (mrem) and a shallow skin dose of 150 mrem during a quarter will note that this constitutes 1% and 0.3%, respectively, of the appropriate annual limits. (See the table below for a listing of the dose limits established by the state of New Jersey).

    The University has established investigational levels at doses considerably less than the dose limits. When a worker accumulates during any part of a year a dose at or above the investigational level, Environmental Health & Safety (EHS) will investigate to determine causes of the dose and to recommend practices to minimize radiation exposure in the future.

    Further information about radiation exposure from radioactive materials taken up internally is provided in Appendix B in the listings of Annual Limits of Intake (ALI), the amount of a specific radioisotope taken internally which will produce a whole body dose of 5000 millirems. For example, Appendix B states that the ALI for H-3 is 80 mCi. If a worker is notified that he or she has had an intake of 80 mCi of H-3 with a resulting dose of 5 mrem, then the table below indicates this dose to be 0.1% of the annual radiation dose limit.

    Organ

    NJ Limit (mrem/yr)

    University Investigation Level (mrem)
    Comments

    Whole Body

    5,000
    100
    Includes dose from external and internal sources
    Lens of Eye
    15,000
    300
    ---
    Extremities
    50,000
    1000
    Extremities include the arm below the elbow or leg below the knee
    Skin
    50,000
    1000
    ---
    Embryo & Fetus
    500 for entire pregnancy
    50
    Applies only when a Declaration of Pregnancy has been submitted
    Occupational exposure of a minor
    10% of the limits above
    50
    Applies to anyone under age 18
    Member of the General Public
    100
    50
    ---

    The ALARA Principle

    Although the University must keep doses of students, staff and visitors below the relevant state dose limits, the University is further required by state regulation to keep doses As Low As Reasonably Achievable (ALARA). This means that the University must work to keep doses as far below the dose limits as can readily be achieved. Consequently the University has established investigational dose levels and will investigate any dose exceeding these levels in an effort to address causes of unnecessary radiation exposure.

    External Monitoring

    Required Monitoring

    Monitoring of external radiation exposure is required for the following persons:

    • Any person using an x-ray diffractometer
    • Persons using radioactive materials in the following amounts and types of use:

    * Monitoring is not required for operations which only involve aliquoting from a stock vial and do not involve any other manipulation of radioactive materials.

    • Declared pregnant workers who work in labs using gamma emitters or high-energy beta emitters (>250 keV)
    • Other persons may be issued monitors at the discretion of the Radiation Safety Officer (RSO).
    Optional Monitoring

    External monitoring can be requested by any person working in a laboratory in which gamma emitters or energetic beta emitters are used, even if that person does not meet the criteria for required monitoring. In such a case, EHS meets with the worker initially to discuss any concerns the worker has and will then initiate radiation monitoring for the next year. After providing dosimetry for a year, EHS meets with the worker again to review doses for the past year and to discuss whether monitoring should be continued.

    Monitoring is not generally provided for persons working in laboratories in which only alpha emitters or low energy beta emitters (< 250 keV) are used.

    How to Request a Monitor Badge

    Use the Radiation Monitoring Service Request Form to submit a request to EHS to request radiation monitoring services. 

    The Rules of Monitor Badge Wear
    • Wear badges so the name label faces toward the source of radiation.
    • Wear the ring badge under gloves to avoid contaminating the badge (but be careful not to throw out the ring badge with the gloves when discarding the gloves as radioactive waste.)
    • Store badges in low radiation background areas.
    • Do not expose badges to elevated temperatures (e.g., don’t store badges on hot sunny surfaces or near radiators).
    • Notify EHS immediately if you suspect you may have received an unusual exposure.
    • Do not wear your badges when you receive medical x-rays or are exposed to other medical sources of radiation.
    • If your badges become contaminated, damaged or lost, call EHS immediately to request replacements.
    • Badges are generally exchanged once a quarter, although badges for declared pregnant workers are exchanged once a month.
    • Turn in your old badges to your badge exchange contact promptly at the end of the wear period, after you receive your new set of badges.
    How to Find Out Monitoring Results

    Monitoring reports are received by EHS approximately six weeks after the end of a monitoring period and forwarded to each Authorized User shortly thereafter. An individual can request his/her radiation exposure history any time by contacting EHS.

    Internal Monitoring

    Radioactive materials can be taken up internally when volatile or other airborne radioactive materials are inhaled and when radioactive materials are absorbed through skin or ingested. Internal uptakes may occur when lab personnel unknowingly handle contaminated objects, when permeation occurs through highly contaminated gloves, or when spills occur. To determine the dose resulting from an intake, bioassays must be performed. For the radioisotopes commonly used at Princeton University, bioassays usually involve urinalysis or external thyroid counting.

    When are Bioassays Required?

    EHS may request bioassays when widespread contamination has occurred in a laboratory, and when skin contamination has occurred. A worker can request a precautionary bioassay at any time. A bioassay is required under the following circumstances:

    When a person uses H-3 exceeding the amounts listed below (which are the amounts a person handles at any one time or the cumulative activity handled by that person during one month):

    Nature of Use Form Activity
    In an open room HTO* and other forms, including nucleotide precursors 100 mCi
      H-3 gas in a sealed vessel 100 Ci
    In a chemical fume hood HTO* and other forms, including nucleotide precursors 1 Ci
      H-3 gas in a sealed vessel 1000 Ci

    * HTO is tritiated water

    When a person uses I-125 exceeding the amounts listed below (which are the amounts a person handles at any one time or the cumulative activity handled by that person during any three month period):

    Nature of Use Form Activity
    In an open room As NaI or other volatile form 1 mCi
      Bound to a non-volatile agent 10 mCi
    In a chemical fume hood As NaI or other volatile form 10 mCi
      Bound to a non-volatile agent 100 mCi
    How to Arrange for a Bioassay

    Thyroid counting is performed at the EHS office and requires no more than ten minutes. Contact EHS to schedule an appointment. Supplies and instructions for urine bioassays are provided by EHS.

    Declared Pregnant Worker Program

    NJDEP’s Fetal Dose Regulations

    The two most important aspects of the NJDEP’s fetal dose regulations are:

    • The fetal dose regulations apply only to a woman who has voluntarily informed her employer, in writing, of her pregnancy and the estimated date of conception.
    • The dose to the fetus resulting from occupational exposure of a declared pregnant woman may not exceed 500 mrem for the entire pregnancy.
    How to Submit a Declaration of Pregnancy

    Any radiation worker who is pregnant or believes that she may be pregnant should contact EHS. All inquiries will be kept in confidence. EHS will take the following steps:

    1. Provide an opportunity to submit a Declaration of Pregnancy. A Declaration of Pregnancy form is included in Appendix E or may be obtained from EHS. If a written declaration of pregnancy is not submitted to EHS, then the worker’s dose continues to be controlled under the normal dose limits for radiation workers.
    2. Provide information concerning risk of fetal radiation exposure.
    3. Evaluate the worker’s dose history and exposure potential. For the type of radiation work performed at Princeton University, it is rarely necessary to recommend reassignment or changes to job duties.
    4. Make recommendations for reducing radiation exposure.
    5. Monitor the worker’s radiation dose with regard to worker and fetal dose limits.

    Research Involving Radiation Work at Other Institutions or Companies

    Any Princeton University employee or student who plans to do radiation work at other institutions must notify EHS before visiting the other institution. The radiation exposure of visitors from Princeton University will be monitored by the host institution, using badges supplied by that institution. However, Princeton is required to keep track of the total radiation exposure received by its employees and students. EHS will contact the host institution and request radiation exposure records.

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    Section 7: Waste Disposal

    The Radioactive Waste Management Program

    Several factors determine the route by which radioactive wastes are disposed. These factors include: half-life, radionuclide, chemical constituents, physical form (liquid or solid), dose rate, and other physical characteristics (is the source sealed and encapsulated or open?).

    • Most solid wastes that contain isotopes with half-lives not exceeding 120 days are handled through the centralized Decay-in-Storage (DIS) Program for ultimate disposal as non-radioactive medical waste.
    • Solid radioactive wastes contaminated with radionuclides with half-lives greater than 120 days are disposed of through a contracted radioactive waste disposal services broker as part of the Off-Site Radioactive Waste Disposal Program managed by EHS.
    • Certain liquid wastes are disposed of through the Sanitary Sewer Disposal Program.
    • All liquid scintillation wastes are disposed of through a contracted radioactive waste disposal services broker as part of the Off-Site Radioactive Waste Disposal Program.
    • Special wastes that include animal or other biological waste, hazardous chemical wastes such as phenol, sealed sources, certain uranium and thorium compounds, radium, or transuranic isotopes are disposed of through special arrangement. Contact EHS to make disposal arrangements.

    Mixed Wastes

    Mixed wastes are radioactive wastes which also contain hazardous waste components regulated under RCRA (the federal Resource Conservation and Recovery Act) regulations. Currently there are limited options for the disposal of mixed wastes, and the options which do exist are often costly. In the laboratory setting the type of mixed wastes most likely to be generated include:

    • contaminated lead
    • certain organic solvents such as chloroform, phenol, toluene and xylene.

    EHS is available to help determine whether specific wastes meet the definition of mixed wastes. Whenever feasible, contact EHS before generating mixed wastes to allow time to determine disposal options or to establish procedures which may prevent a mixed waste from being generated. The flow charts at the end of this section will allow a user to determine the basic disposal route for any waste form and will either refer the user to detailed disposal procedures or to EHS for further help.


    Waste Disposal Procedures

    The flow charts at the end of this section will allow a user to determine the basic disposal route for any waste form and will either refer the user to detailed disposal procedures or to EHS for further help.

    Summary of Radioactive Waste Disposal Procedures

    Step 1: Is this animal or other biological waste?

    • Yes - call EHS for procedures
    • No - go to Step 2

    Step 2: Is this mixed waste?

    • Yes - call EHS for procedures
    • No - go to Step 3

    Step 3: Is this liquid scintillation counting waste?

    • Yes - go to LSC procedures
    • No - go to Step 4

    Step 4: Is the waste liquid?

    • Yes - go to liquid waste disposal chart
    • No - go to Step 5

    Step 5: Is the waste solid?

    • Yes - got to solid waste disposal chart

    Liquid Scintillation Counting Wastes

    • The use of toluene-, xylene- and pseudocumene-based solutions is prohibited.
    • LSC solutions must have a flashpoint of 140º F. or greater. Acceptable LSC solutions include:
      • BCS
      • CytoScint ES
      • Formula 989
      • BCS-NA
      • Ecolite
      • Scintiverse BD
      • BetaMax ES
      • Ecolume
      • Universol ES
      • Bio-Safe II
      • Econo-Safe
      • Fisher’s ScintiSafe solutions
      • Bio-Safe NA
      • Ecoscint
    • All LSC wastes, regardless of the isotope, are disposed of through an off-site disposal program.

    LSC Waste Disposal Procedures

    1. Obtain a lined 5-gallon pail from the department waste contact or from EHS.
    2. To minimize costs, certain isotopes should be segregated from other isotopes. EHS will provide separate instructions for segregating LSC wastes.
    3. Place tightly closed vials in the lined pail.
    4. Do not place gloves or anything except vials in the pail.
    5. Make an entry on the waste card each time wastes are placed in the pail.
    6. When the pail is full, securely twist closed and seal the liner, using tape, string or twist ties.
    7. Contact the department’s waste contact to take full pails to the department’s waste storage facility.
    8. Contact the department waste contact or EHS for supplies. Call EHS with any questions.

    Liquid Waste Disposal Procedures

    A flow chart for liquid radioactive waste disposal

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    Section 8: Transporting & Shipping Radioactive Materials

    Transfers within the University

    Whenever radioactive material is moved from a laboratory to any other facility, even to adjacent buildings, package it and move it in a way that will avoid spilling the material and unnecessary exposure to anyone. Take the following steps:

    1. Contact Environmental Health & Safety (EHS) in advance, if the material is being moved along or across any public street. Under some circumstances, the transportation of radioactive materials across campus must comply with U. S. Department of Transportation (USDOT) regulations. Normally it will be easy to comply with USDOT requirements. EHS will advise you on how to comply.
    2. Surround any container of radioactive liquid with sufficient absorbent material to absorb at least twice the volume of liquid. Use materials such as vermiculite, paper towels, or absorbent padding.
    3. Provide adequate shielding.
    4. Label the inner container of radioactive materials with a Radioactive Materials label. Label the outer package with the names and addresses of the labs that the package is coming from and going to.

    Transfers between Princeton University and Other Institutions

    Do not ship or transport radioactive materials to another institution without contacting EHS in advance. In order to transfer and ship radioactive materials properly, take the following steps:

    1. Contact EHS well in advance of the planned shipment date, using the Hazardous Materials Shipping Request Form. EHS will contact the other institution to obtain a copy of its license and to make arrangements with the other institution for receipt of the package and will advise the Authorized User and lab personnel about packaging and shipping requirements.
    2. Plan to use a commercial carrier such as a Federal Express to ship radioactive materials. Do not use a private vehicle to transport radioactive materials because the transportation regulations are complex and because any person transporting hazardous materials must receive specialized training.

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    Section 9: Radiation Producing Machines

    A radiation-producing machine is defined to be either any machine primarily intended to produce radiation, such as:

    • x-ray diffraction or x-ray fluorescence units
    • electron microscopes
    • medical x-ray equipment
    • x-ray radiography units
    • cabinet x-ray systems
    • particle accelerators

    or any electrical equipment which is not primarily intended to produce radiation but produces radiation greater than 0.5 mrem/hour at any readily accessible point five centimeters from its surface. Any electronic tube operating at a potential above 10 kV should be considered as a possible source of x-rays even though it may not have been designed for that purpose. Such equipment may include:

    • high voltage rectifiers
    • transmitting tubes (such as those found in commercial and some amateur radio transmitters)
    • high power amplifying tubes (e.g., klystrons and magnetrons) used to produce microwave fields
    • discharge tubes in which the gas pressure may be varied while studying electrical discharge.

    Consult with Environmental Health & Safety (EHS) if there are questions concerning the radiation-producing potential of any equipment.

    The possession and use of these radiation-producing machines is regulated by the New Jersey Department of Environmental Protection (NJDEP).

    Acquiring Radiation-Producing Machines

    Purchasing Machines

    Any proposed purchase and installation of a radiation-producing machine must be reviewed and approved in advance by the Radiation Safety Officer. EHS will register the new machine with NJDEP.

    Loans or Other Transfers of Machines

    EHS must be notified in advance when any radiation-producing machine is planned to be acquired as a loan, transfer or a gift from another institution or from any individual or department at the University. EHS will register a new machine or will update any previously registered machine’s registration with the NJDEP.

    Precautions and Guidelines for Analytical X-Ray Equipment

    • Call EHS for radiation surveys and monitoring of any newly installed or relocated machines and especially when the machine has been modified for special experiments.
    • A survey meter with a low-energy NaI detector, rather than a G-M detector, is the most appropriate detector to survey for the low-energy x-rays associated with x-ray diffraction work.
    • Under normal operating conditions, always turn off the machine high voltage before opening the enclosure (for enclosed beam systems) or before taking any action which could expose the primary beam path (for open beam systems).
    • Each day before using the machine, open and close the shutter a few times to check that the shutter is functioning properly.
    • Never assume that the unit was left in a safe working condition by the previous user. Check the shielding and interlock status before turning the unit on.
    • Do not bypass any safety device or interlock without the approval of the person responsible for the machine. When any portion of the safety devices are disabled, post a conspicuous sign stating the date, your name and listing what has been disabled. Return the machine to its unmodified state with all interlocks and safety devices operational as soon as possible.
    • Do not work near the open, unshielded beam. However, if it is necessary to work near the unshielded beam (e.g., during system alignment):
      • Reduce the beam current and high voltage to the lowest possible settings to reduce exposure rates.
      • Keep hands and body as far as possible from the beam by using appropriate alignment tools.
      • You are in a potentially hazardous situation. Think before each step.
    • Know what you are doing and where to expect problems. Be aware of the dangers. Do not work in a hurry or allow yourself to become distracted.
    • In the event of a known or possible exposure to the beam, notify EHS immediately (see Section 1, Radiation Spill & Incident Procedures).

    Precautions and Guidelines for Electron Microscopes

    • Call EHS for radiation surveys and monitoring of any newly installed or relocated microscope, when the machine has been modified for special experiments, and following any service work in which the column has been opened.
    • Uranium, often as uranyl acetate, may be used as a stain in some electron microscope procedures. Uranium is regulated somewhat differently than other radioactive materials and can be purchased directly by the user from a vendor. However, once uranium compounds are brought onto the Princeton University campus, the compounds fall within the scope of the University’s NJDEP radioactive material license. Some degree of inventory control is required and waste materials must be disposed of as radioactive waste. Contact EHS when uranium compounds are acquired.

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    Appendix A:  Contamination Surveys

    Types of Contamination

    • Removable contamination can be readily removed using proper decontamination procedures. Removable contamination in any amount may present both an external and internal hazard because it can be picked up on skin and possibly ingested.
    • Fixed contamination cannot be readily decontaminated. Fixed contamination generally does not present a significant hazard unless the material comes loose or is present in such large amounts that it presents an external radiation hazard.

    Types of Surveys

    • Meter surveys, using Geiger detectors or scintillation probes, can identify gross contamination (total contamination consisting of both fixed and removable contamination) but will detect only certain isotopes.
    • Wipe surveys, using “wipes” counted on a liquid scintillation counter or a gamma counter, can identify removable contamination only but will detect most isotopes used at Princeton. Wipe tests are the most versatile and most sensitive method of detecting low-level contamination in the laboratory.

    Survey Instrumentation

    • The portable Geiger-Muller (G-M) survey meter is best used for P-32, a high energy beta emitter, and other high energy beta and gamma emitters, such as Co-60, Zn-65, Cs-137, and U-238. A G-M meter can also be used to identify areas heavily contaminated with lower energy betas, such as C-14 or S-35, for which the G-M meter has a relatively low efficiency. G-M meters should not be used to survey for I-125 contamination, since G-M meters will detect I-125 only when there are very high levels of contamination.
    • The portable thin crystal NaI scintillation survey meter is used to locate I-125 contamination and to conduct surveys around low-energy x-ray sources such as x-ray diffractometers and electron microscopes.
    • The liquid scintillation counter, used for counting wipe tests, is not portable but is the most versatile counting instrument because it has a high counting efficiency for a wide range of radionuclides.
    • Gamma counters are not portable and are used to count wipe tests for photon emitters, such as Cr-51 or I-125.

    How to Perform a Meter Survey

    1. Check the survey meter’s battery by turning the meter knob to the battery test position. If the battery is adequately charged, the meter needle will swing to the battery test position on the meter face. Replace the batteries if the batteries are low.
    2. Perform an operational check the first time you use the meter each day or when you suspect it may have been misused or damaged. Look at the calibration sticker on the side of the meter and note what the expected reading for the operational check source should be. Turn the meter on and turn the meter’s multiplier switch to a setting that will measure the check source and will provide a mid-scale reading but will not cause the needle to swing beyond full scale. For a Ludlum G-M survey meter the multiplier knob should generally be set to the X1 position. Place the probe firmly against the check source on the side of the meter and note the meter response. If the observed meter response differs from the expected response by more than 20%, the meter should be considered nonfunctional and should be taken out of service.
    3. Take the meter to an area away from sources of radiation and note the meter background reading. Typically, the background for a G-M meter with a pancake survey probe should be less than 100 counts per minute (cpm) while the background reading for a meter with a NaI scintillation crystal should be less than 300 cpm. If the meter’s background reading is substantially greater than expected, confirm that there are no unexpected sources of radiation or radioactive materials in the vicinity, and then call Environmental Health & Safety (EHS) to report a contaminated meter.
    4. Do not cover the probe surface with parafilm or other protective covering. Parafilm and similar materials will shield the low energy betas from C-14, P-33 and S-35 and will prevent the meter from detecting contamination.
    5. Slowly move the probe about 1 centimeter above the area of interest.
    6. If an item or area with a sustained count rate more three times background is found, the item or area should be considered to be contaminated.
    7. Immediately label the area or item and promptly decontaminate it. Decontamination procedures are provided in Section 1. If an area cannot be decontaminated, the contaminated area should be marked and labeled to indicate the isotope, date and level of contamination.
    8. Sometimes, especially in the presence of other radioactive materials, the meter survey may be equivocal. When the meter survey indicates that low level contamination may be present, a wipe survey should be performed to confirm or disprove the presence of contamination.
    9. Document the survey results whenever contamination is discovered or if 250 µCi or more have been handled. Record survey results in the laboratory survey log. This is a University requirement.

    How to Perform a Wipe Test

    1. Wipe surveys must be performed when H-3 is used and is the survey method of choice to detect the presence of low levels of removable C-14, P-33 and S-35 contamination. Wipe surveys should also be performed to confirm the presence of contamination when a meter survey suggests that low level contamination may be present.
    2. Using a piece of filter paper (about 1” in diameter), Q-tip or other swab, wipe the area being surveyed. If the area is very large, subdivide it into smaller areas and use several wipes to better pinpoint the location of contamination. For some surfaces, including skin and clothing, the wipe media should be moistened with water or other appropriate solvent.
    3. Prepare the sample for counting as suggested in the counter’s operating manual. Analyze the wipe samples in a liquid scintillation counter for H-3 and other beta emitters and preferably in a gamma counter for Cr-51 and I-125.
    4. Sample activity is determined by dividing the sample count by the counter’s efficiency for the isotope in question. The counter’s operating manual should provide information about efficiencies and activity determination.
    5. Call EHS with questions about liquid scintillation and gamma counter use.

    Radioactive Survey Log.pdf:   Use this log to record your laboratory contamination surveys.

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    Appendix B: Radioisotope Fact Sheets

    Radioisotope Fact Sheets: Click here for fact sheets for various radioisotopes used at Princeton University.


    Appendix C: Decay Calculator


    Appendix D:  Staff

    See the Staff sidebar at the top of this page.


    Appendix E: Declaration of Pregnancy Form

    Click here for the Declaration of Pregnancy Form.

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    University Policies


    Eating & Drinking in Radioisotope Laboratories (adopted 6/2003)

    Eating, drinking, or other similar activities (consuming medicines, applying cosmetic products, etc.) in rooms labeled as radioisotope use areas is not permitted except under the following conditions:

    • Any area in which eating and drinking occur must be designated as an Eating/Drinking Area. The Radiation Safety Committee must grant specific approval to an Authorized User to designate an area to be an Eating/Drinking Area. The Committee will take into account the nature of the radioisotope activities in the lab before approving an Eating/Drinking Area, e.g., a laboratory using I-125 may not be granted approval.
    • In general, there must be a minimum separation of 5 feet between any locations in which radioactive materials are used or stored and an Eating/Drinking Area. However, the Committee may allow smaller separations if the Committee determines that factors such as the presence of walls or other physical barriers or the nature of the radioactive source (e.g., a sealed source) will prevent contamination from readily spreading into the Eating/Drinking Area.
    • An Eating/Drinking Area must be designated with signage stating “Eating/Drinking Area - No radioactive materials are permitted within this area.”
    • Radioisotope work and storage areas must be designated with signage, tape, or other labeled barriers to indicate that radioactive materials are stored or used beyond this point.
    • Laboratory personnel must remove gloves and wash and survey hands after working with radioisotopes, and prior to entering an Eating/Drinking Area.
    • A waste receptacle must be provided within the Eating/Drinking Area and used only for non-laboratory trash.
    • If the layout of the lab is such that it is necessary to carry food or beverages to the Eating/Drinking Area by passing through the radioisotope use area, it is not permitted to eat or drink while passing through the radioisotope use area, and personnel carrying food or beverages must pass through the radioisotope area without lingering.
    • EHS shall conduct spot checks for contamination within and at the boundary of Eating/Drinking Areas as part of its routine laboratory surveys.
    • Permission for an Eating/Drinking Area within a laboratory will be revoked if EHS finds radioactive material or contamination within an Eating/Drinking Area or if violations of these requirements are observed.

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    Protective Clothing for Radioisotope Users

    Gloves, a full-length laboratory coat, and closed-toe shoes, are required to be worn by any person working with an open radioactive source in an amount equal to or exceeding 0.01 times the quantity given in Appendix C of 10CFR20 (incorporated by reference into New Jersey radioactive materials regulations) for any radioisotope, if such work creates a reasonable potential for contamination. For the most commonly used isotopes, these quantities are 1 µCi for C-14, 10 µCi for H-3, 0.01 µCi for I-125, 0.1 µCi for P-32, and 1 µCi for S-35. However, it is recommended that appropriate protective clothing, including gloves, a full-length laboratory coat, and closed-toe shoes should be worn at all times for work with any open radioactive source, regardless of the source activity. Wearing sandals or open-toed shoes, when handling the quantities specified above, is prohibited.

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    Security of Radioactive Materials

    All radioactive stock materials and sealed sources must be stored in a secured container or secured storage area when not in use. Any room in which an unattended sealed source is being used must be secured. Exceptions must be approved in writing by the Office of Environmental Health and Safety. A stock material is defined to be radioactive material as provided by the vendor and does not include material withdrawn from the original stock by a researcher for experimental use. This policy applies to materials for which EHS approval and authorization is required and does not apply to generally-licensed devices, such as smoke detectors, static eliminators, electron capture detectors, exit signs, etc.

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    Training for Personnel in Radioisotope Laboratories

    The Radiation Safety Committee establishes the following training requirements for laboratories authorized to work with “open” sources of radioactive materials: 

    1. Initial Radioactive Materials Safety Training must be completed by any person who plans to handle “open” sources of radioactive material.  Such training must be completed before a person handles radioactive materials or observes procedures involving radioactive materials.
    2. Initial Radioactive Materials Safety Training will consist of the review of 1) online Radiation Basics modules and completion of a Radiation Basics test, and 2) attendance at a Radioactive Materials Safety Class.
    3. Authorized Users, lab managers and individuals responsible for radiation safety functions in a laboratory must complete the Initial Radioactive Materials Safety Training program, even if those persons do not use radioactive materials.  These persons must also complete annual radiation safety refresher training.
    4. Individuals subject to these training requirements and who have completed radiation safety training at other institutions are required to complete Princeton University’s initial radiation safety training program.
    5. In addition to the initial radiation safety training described in Item 2, each person who will handle radioactive materials must be provided with procedure-specific training.  Such training will be provided by the Authorized User or experienced open-source radioactive materials workers designated by the Authorized User.  This training must address the laboratory’s procedures for the following topics: a) How to set up and label a work area, b) How to conduct a survey, c) How to segregate and dispose of waste, d) How to segregate and dispose of waste, and e) How to complete laboratory rad records such as inventory, survey and waste records. Each lab is responsible for making sure, through training and supervision, that its radiation workers know how to complete all these requirements of the University’s radiation safety program.  The PI or experienced radioisotope users in a lab are responsible for providing this training and supervision.
    6. Each person defined to be an open-source radioactive materials worker must complete annual refresher training provided by EHS.  See the definition of open-source radioactive materials worker in Item 7).
    7. EHS will maintain a registry of open-source radioactive materials workers.  Labs with active authorizations for open sources of radioactive materials will provide EHS with a quarterly update of open-source radioactive materials workers.  At the time of each update, a lab’s open-source radioactive materials workers will include those people who used radioactive materials within the previous six months, those people currently conducting experiments utilizing radioactive materials, those people with known plans to use radioactive materials in the near future, the Authorized User, the lab manager and any person who functions as the lab radiation safety contact.
    8. Those persons who are members of or otherwise frequent lab spaces with active authorizations for open sources of radioactive materials must complete the online Radiation Safety Awareness Training Program and must complete it as soon as practicable after joining the lab.  Visitors and other individuals who will work in the lab for periods of time not exceeding one month are not required to complete the radiation safety awareness training. 
    9. The Radiation Safety Awareness Training Program for Non-Radioisotope Users consists of an online slideshow and test which must be successfully completed.

    Researchers who handle sealed or plated radioactive sources only must complete initial radiation safety training for sealed source users.

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    Transferring Radioisotopes between Princeton University Laboratories (adopted 2/2004)

    Transfers of radioactive materials between Princeton University Authorized Users are permitted under the following conditions:

    • Transfers of sealed sources or plated sources are not permitted without written authorization from EHS.
    • Transfer of open sources are permitted under the following conditions:
      • The lab which originally possesses the material (the transferring lab) is responsible for ensuring that the lab asking to receive the material (the recipient lab) is authorized to possess the radioisotope in question, prior to the transfer.
      • In order to determine whether the recipient laboratory is appropriately authorized, the transferring laboratory may either contact EHS to inquire about the recipient laboratory’s authorization prior to the transfer or the transferring lab may follow the EHS web-based procedure for verifying the recipient’s lab’s authorization and for sending e-mail notification of the transfer to EHS. If the transferring laboratory uses the web-based procedure, prior notification to EHS and prior approval by EHS of the transfer is not required.
      • The transferring lab must make a notation on the original Vial Use Log indicating that the transfer has occurred.
      • When appropriate (for example, when an entire vial is being transferred), EHS will make the appropriate inventory adjustments and will provide the recipient lab with a new Vial Use Log for the transferred vial.
      • Transfers must comply with requirements for transporting materials, as described in the Princeton University Radiation Safety Manual.

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    Uranium & Thorium Use

    The federal and state governments consider that certain uranium- and thorium-containing compounds, such as uranyl acetate and thorium nitrate, represent less of a radiation hazard to users than many other radioactive materials.  As a result, these uranium and thorium compounds are regulated differently than most radioactive materials used at the University.  Regulations allow you to purchase these compounds directly from the vendor without a radioactive materials license.  However, the regulations also require educational institutions to limit their entire campuswide inventory to no more than 3.3 pounds of uranium and thorium.  This means that you must be sure to notify EHS about your orders and inventory of uranium and thorium.

    Planning to Use Uranium or Thorium

    Consult with the Radiation Safety Officer (RSO) before ordering or using uranium or thorium, even if you only plan to use very small amounts or concentrations.  The RSO must include your uranium and thorium materials in the overall University inventory and will work with you to determine disposal needs.  Additionally, the RSO may arrange for EHS to conduct quarterly contamination surveys in your lab space.

    Training

    If you plan to work with uranium or thorium compounds, complete the online Radiation Safety Training for Uranium and Thorium Users. Go to the Employee Learning Center and log in.  Click on Training by Department  > Environmental Health & Safety. On the Environmental Health & Safety tab, click on Radiation Safety and find the listing for Radiation Safety Training for Uranium and Thorium Users

    Waste

    You may be required to dispose of your uranium and thorium wastes as radioactive waste, depending on the amounts you use.  EHS will work with you to determine the appropriate way to get rid of your waste.