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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  • 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 A stock material is radioactive material as provided by the vendor and does not include material withdrawn from the original stock for experimental use.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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Colt Greer
Assistant Director and RSO

Chelsea McDonnell
Health and Safety Technician