Greening Up The Lab: Sustainable Research Practices

April 3, 2018

There are many opportunities, large and small, for researchers to practice an ethos of sustainability in the laboratory.

The most impactful of these center around the themes of conservation, waste reduction and resource management.


Everyone knows labs are big consumers of energy, which is why even modest conservation efforts can lead to significant environmental (and cost) benefits.

Cold Storage

Freezers are often the biggest users of electricity in the lab. According to Lab Manager magazine, a single ultra-low temperature freezer draws as much energy as an average domestic household. Follow these tips to minimize energy consumption and to keep your cold storage units running their best.

  • Regularly change or clean filters and exposed refrigeration coils behind refrigerators/freezers and clean the door seal to improve contact on sealing surfaces
  • Consolidate samples and reagents into a single fridge/freezer to reduce the number of fridges and freezers required - or share with neighboring labs
  • Be sure to turn off/unplug units not in use

At Princeton, the Minus 80 freezer monitoring program tracks temperatures and sends alerts when a freezer gets too warm or too cold. Wireless probes check for doors left open and other energy-wasting practices, and data collected over time enables sustainability initiatives by allowing for monitoring and improvement of lab protocols, as well as flagging of poorly performing units.

Labs at Princeton interested in adopting Minus 80 should contact EHS at [email protected].

The Laboratory Freezer Challenge, launched in January 2017, encourages best practices in cold storage management, such as periodic defrosting, cleaning out of unneeded materials, temperature fine tuning, equipment upgrades and space sharing.

“Most cold storage units are ignored until they fail, and many of the samples stored in those units remain there for years, or even decades,” says Allison Paradise, executive director at My Green Lab. “The Freezer Challenge encourages people to take a more active role in managing their freezers/refrigerators and their samples.”

The Freezer Challenge is co-sponsored by My Green Lab and the International Institute for Sustainable Laboratories (I2SL). The annual contest pits individual labs against each other in friendly competition; scorecards are submitted and labs ranked against peer institutions.

Good freezer management is not just environmentally friendly—it’s good for your pocketbook. Cleaning out freezers and sharing space with colleagues results in labs requiring fewer cold storage units, which can dramatically reduce costs, Paradise says.

One CDC lab participating in the challenge slashed operating costs by $10,000. A Harvard lab saved $2500 a year, allowing it to spend money earmarked for a new freezer on other priorities.

Fume Hoods

Another big consumer of electricity is fume hoods, which use high-power fans to ventilate the lab. Fume hoods must run constantly to maintain pressure and flow rates, which is why a single fume hood can consume between 1 and 1.5 times the energy used by the average residential home, according to a study from American Auto Matrix.

The best way to reduce fume hood energy consumption is to close hood sashes when not in use. In a variable flow fume hood, this reduces fan speeds to a minimum, as less air displacement is needed. See the EHS website for more information.


Flow control also matters when looking to reduce water consumption. Flow reducing valves, timers and automatic shut-off mechanisms can all be utilized to conserve water.

When upgrading water-using equipment, such as autoclaves, x-rays and dishwashers, choose models specifically designed with water-conservation features.

Batch rinsing, reducing rinse cycles and running dishwashers only when they are full are proven ways to save water. In some situations (e.g. vivariums), the final batch of water used to wash a piece of equipment can be re-used in preliminary rinses of other equipment. Counter-current rinsing utilizes multiple connected rinse tanks, with fresh water flowing from the final rinse tank to preliminary tanks. This allows preliminary rinses to be done in slightly used water, saving the fresh water for the final rinse.

Significant water saving can be achieved in many labs by changing distillation practices. Distillation, a common lab procedure used to separate materials, involves running water through a condenser, sometimes for hours at a time.

Rather than running the tap continuously and draining used water into a sink, a bucket of ice water along with a common fish pump can be used to re-circulate water through the apparatus, both saving water and preventing wide-scale flooding should the hose accidentally pop off.

Other Conservation Methods

There are many other ways to conserve resources in the lab. Use of efficient electric lighting, design choices utilizing daylight and optimized placement of ventilation and HVAC systems, and updating or rightsizing lab equipment are all ways to save energy and cut costs in the laboratory.

For additional tips on conserving energy and resources in the lab, see the Best Practice Guides on the I2SL website:

Waste Reduction and Resource Management

Cutting the waste stream is another effective way to green up lab practices. This can be achieved by both reducing the amount of material purchased and used, and finding alternatives to disposal such as sharing, redistribution and recycling.

Good resource management helps to avoid redundancies and unnecessary purchases, as well as reducing the chance surplus substances will eventually find their way to the waste stream. Inventory systems should be in place to allow researchers to know what materials are on site and how they are earmarked for use.

Don’t purchase more of a chemical than you expect to use in the foreseeable future; researchers should strive to practice “just in time” purchasing of reagents. Remember, disposal of large surpluses of unused or unwanted chemicals will certainly outweigh any savings associated with bulk purchases.

Microscale Chemistry is an increasingly popular way to conserve resources in the lab. Scaling down experiments to a practical minimum reduces the total amount of waste generated and cuts down on ventilation needs. It also has safety, cost and time management benefits.


Tracking of hazardous substances opens the possibility of substitution of hazardous materials with less- or non-hazardous alternatives. This can include cleaning materials, catalysts and reagents.

EHS offers specific guidance on alternatives to minimize or eliminate the use of hazardous materials when cleaning, sterilizing, dehydrating and rinsing equipment. Consult with us to learn more about hazardous material substitution.

FUN FACT: Professor Paul J. Chirik of Princeton University received the 2016 Presidential Green Chemistry Challenge Academic Award for his work identifying industrial catalysts that can substitute for platinum, potentially reducing the mining of many tons of ore. 

Exchange and Reuse

A strategy increasingly used by universities is setting up exchange programs for surplus laboratory resources. At the University of Michigan, a campus-wide reuse initiative includes 239 labs sharing unused and unexpired chemicals, equipment and other materials.

Princeton’s surplus program, recently renamed Resource Recovery, is a great source for furniture, office equipment and electronics.

Managing Hazardous Waste

Proper disposal of hazardous materials is fundamental to minimizing the environmental impact of the lab. It’s also the law.

EHS is your partner in proper disposal of chemical, biological and radioactive waste. Learn more about waste management on the EHS website.

Types of Chemical Waste

Used chemicals are considered hazardous if they are ignitable, corrosive, unstable or contain toxic metals or organics. Improper management of such materials can lead to significant environmental harm, as well as fines and criminal penalties.

Packaging, Storage and Disposal

Chemical waste is placed in labeled, sealable containers that must remain closed except when being filled. Containers are stored until pickup at or near the area where the waste is generated.

Waste is collected directly from laboratories and other points of generation on Princeton University's main campus on Thursdays (excluding holidays and closings).

To request a pick-up, fill out the Waste Removal Request Form. Requests placed before 5 p.m. on Wednesday are included in the following day’s collection.

Waste eligible for removal:

  • Non-regulated experimental waste and debris 
  • Hazardous waste 
  • Spill debris or grossly contaminated materials
  • Used pump oil
  • Mercury containing articles

Regulated Medical Waste

Certain materials generated by research lab activities must be disposed of as regulated medical waste, or RMW. RMW is categorized as either solids (gloves, flasks, etc.), liquids (cultures, specimens, etc.) or sharps (needles, blades, etc.), with different disposal procedures for each.

Solids are usually autoclaved (sterilized with heat) before disposal in a labeled, regulated medical waste box. Sharps are also disposed of in specialized containers. Both sharps and solids are picked up by a waste contractor specializing in processing of these materials. Liquid waste is sterilized with bleach or autoclaving before disposal.

Labs requiring medical waste boxes or sharps disposal containers should contact their departmental supervisors.

Takeaway Tips

Here are 10 tips for great ways to start your journey toward greening up the lab.

  1. Keep freezers clear of frost build-up and dispose of outdated samples.
  2. Keep refrigerator/freezer filters and coils clean and free of obstructions.
  3. Substitute hazardous cleaning and sterilizing substances with non-hazardous ones.
  4. Share resources when possible to avoid unnecessary purchases.
  5. Close variable speed fume hoods when not in use 
  6. Follow proper waste disposal procedures.
  7. Consider green alternatives when replacing or upgrading equipment.
  8. Follow manufacturer recommendations when replacing HVAC and water filters.
  9. Control water flow with solenoid valves, timers and automatic shut-off valves. Consider using a pump instead of a running tap to cool condensers during distillation.  
  10. Set up inventory procedures to allow for effective resource management.

Updated April 2019