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Safety Blog

Just When You Thought Your Lab Was Safer

By Ken Roy

Posted on 2023-02-01

The Unknown or Unaware

A biology teacher in a high school oceanography course had her students set up aquariums and create an experimental design incorporating different types of environmental conditions. Plans were made to implement the experiment and collect laboratory data on various species of tropical fish, considering the different factors. Unfortunately, two days after setting up the aquariums, a major “fish kill” occurred.  Undaunted, the biology teacher used this as a “teachable moment.” She had students investigate the unknown cause of the carnage. It was determined that relatively high concentrations of copper in the water were the agents of destruction.

This is only one example of how teachers and administrators may assume their science labs are safer, when in essence, there may be a number of unknown hazards and resulting health and safety risks of which they are unaware. Increased enrollments, renewed emphasis on hands-on laboratory science, numerous master teachers retiring and neophyte teachers entering service, and building/renovation programs are major factors potentially affecting the level of safety in our school laboratories.  

Board members and school superintendents need to be aware of areas for potential safety concerns resulting from both known and unknown safety hazards in typical middle and high school science laboratories. This knowledge will help them make sound fiscal, curricular, personnel, and safety policy decisions.

This blog post was written to simply help raise laboratory teachers’, supervisors’, and administrators’ levels of awareness regarding numerous and potentially unknown safety hazards in labs. This information will be helpful for science educators seeking to educate and work with administrators. Administrators can then be advocates for change, leading to improvements in the science laboratory.  

Examples of Unknown or Unaware Potential Hazards/Resulting Risks

1. Air quality. The National Fire Protection Association (NFPA) 45 requires laboratory ventilation to be continuous and never recycled. This applies not only to laboratories using hazardous chemicals, but also to preparation rooms, chemical storerooms, fume hoods, and spray booths. Filters that are not of high quality and effectiveness and lack an air filter replacement schedule can make for a dangerous laboratory environment, especially when using flammables, toxins, etc. (See Laboratory Indoor Air Quality and Safety at

2. Water quality. Laboratory water sources should be regularly tested by a certified and state approved testing laboratory. Contaminants including radon gas, lead, copper, nitrates, methane, hydrogen sulfide, and more can make for an unsafe laboratory environment, including those in tap water in sinks, eyewash and safety showers, and other water sources. (See EPA Water Quality Standards Handbook at

3. Electricity. All electrical receptacles in labs need to be Ground Fault Interrupter- (GFI) protected. Section 1926.404(b)(1) of the Occupational Safety and Health Administration’s (OSHA) Wiring Design and Protection standard does not require ground fault circuit interrupters (GFCIs) to be tested. However, 1926.20(b)(2) does require the frequent and regular inspections of equipment. The instructions included with the devices indicate that they should be tested monthly. A non-functioning GFI could subject the user to a shock or worse: electrocution. (See Electrical Safety in the Laboratory at

4. Heavy Metals. Mercury and other heavy metals can be found in lab equipment such as thermometers, florescent bulbs, barometers, sphygmomanometers, and more. Depending on the type and amount, exposures to mercury can damage the nervous system, kidneys, liver, and immune system. Breathing mercury vapors can harm the nervous system, lungs, and kidneys. Mercury vapors can pass easily from the lungs to the bloodstream. Don’t assume all the sources of mercury have been removed from the laboratory. (See Mercury by the National Institute for Occupational Safety and Health (NIOSH) at,harmed%20from%20exposure%20to%20mercury.)

5. Asbestos. In 1978, the Environmental Protection Agency (EPA) banned spray-applied surfacing materials for purposes not already banned. Many older school labs were to be inspected and tested for asbestos. Once located, they must be appropriately removed or embedded with a barrio to prevent exposure. If the school building has not been appropriately inspected on a required schedule for asbestos, especially during renovations, occupants may be exposed from potentially asbestos-laden locations such as floor/ceiling tiles, walls, burners, laboratory table tops, and more. (See EPA Actions to Protect the Public from Exposure to Asbestos at    ,These%20uses%20remain%20banned.)

6. Hazardous Chemicals. Potentially hazardous chemicals may be included in a laboratory inventory. In many cases, appropriate storage reduces potential exposure. However, chemical containers ignored over time can decompose, crack, and have other damage that exposes occupants to chemicals. Chemical storerooms, prep rooms, and labs need to have appropriate storage protocols and regular inspections to make sure hazardous chemicals are secure. (See What types of hazardous chemicals are present in laboratories? at,currentlyhas%20rules%20that%20limit%20exposures%20to%20approximately400%20substances.)

7. Personal Protective Equipment (PPE). PPE needs to be inspected after and before use to make sure their integrity has not been compromised. Goggles can develop cracks, gloves can have tears, and other types of PPE may have damages. Each allows for exposure to biological, chemical, and physical hazards. (See Personal Protective Equipment at,chemicals%20and%20the%20process%20used.)

8. Walls. Older laboratory walls and barriers may have hazards such as lead paint, asbestos, and more, as noted previously. Peeling wall paint is a signal that testing should be done to prevent potential exposure. (See About Lead-Based Paint at,and%20in%20extreme%20cases%2C%20death.)

9. Radiation. Radioactive ionizing materials were included in science activity kits well into the 1970s. These kits are often forgotten in the back of the storeroom. Ongoing exposure can be hazardous to the health of employees and students. Nonionizing radiation sources (UV, lasers, etc.) could also potentially cause health hazards if improperly operated in the laboratory. (See Radioactive Material in the Science Classroom at

10. Biohazards. Exposure to potential biohazards including microbes (bacteria), mold spores, bloodborne pathogens, and more can be potentially serious, health-wise. Appropriate safety protocols need to be in place when selecting lab activities. For example, students should not be allowed to collect bacterial samples in the school, then culture them. (See Laboratory Hazards and Risks at,yet%20they%20are%20frequently%20overlooked.)

11. External Factors. Factors outside of the laboratory, including issues with roofing materials, oil-based paints, custodial chemical technology revolution, custodial mechanical technology revolution, propane buffers, and so on can potentially expose lab occupants to chemical and physical hazards. These can be in the form of particulate, gases, fumes, and so on and be breathed into lungs, potentially causing health issues. (See Potential Chemicals Found in Building Materials at

12. Personnel. OSHA requires appropriate safety training in dealing with potential safety hazards. Untrained personnel often effect unsafe work practices that can put other employees and students in harm’s way. (See Training Requirements in OSHA Standards at

Final Thought

Once science educators are aware of typical unknown hazards, they need to take steps to ensure a safer working environment. They should follow up by contacting administrators, supervisors, and facilities directors as needed to make sure appropriate laboratory testing of water, air quality, and other factors is conducted.  For a safer teaching/learning environment, they should also review the testing results to make sure any hazards are addressed. Under OSHA guidelines, as employees, you have a right to review the original laboratory reports submitted to your employer.  

Remember, laboratories are normally potentially unsafe places, given the potential biological, chemical, and physical hazards associated with laboratory activities. This is why a potential hazard analysis, resulting risk assessment, and appropriate safety actions must be done before laboratory work is initiated. The unknown hazards noted here could definitely make for an unsafe teaching/learning laboratory environment.

Submit questions regarding safety to Ken Roy at Follow Ken Roy on Twitter: @drroysafersci.

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