In middle and high school science instructional spaces (laboratories and classrooms) and associated areas (prep rooms and storeroom), students and staff often work with potentially hazardous biological, chemical, and physical materials. Science teachers need to be involved in the appropriate purchase, use, storage, and disposal of these materials that can present health and safety risks. Science instructional space and associated area waste disposal protocols are critical for ensuring the safer handling and proper disposal of various types of waste generated during hands-on activities and demonstrations.    

Instances have been reported in which teachers have forgotten to appropriately remove these hazardous wastes, especially chemical types. For example, peroxide-forming chemicals are a class of compounds that can form shock-sensitive explosive peroxide crystals over very short timelines. Many of the organic solvents commonly used in laboratories are peroxide formers such as ethers, acetals, and ketals. In some instances, a state bomb squad has had to be called in to remove old peroxide chemicals with crystals growing on the container cap, given the high risk of explosion and injury. The bottom line is this: Before a teacher purchases a potential biological, chemical, or physical hazardous material, they need to know and plan in advance for the means by which it will need to be disposed of. Make sure legal safety standards and better professional safety practices are addressed.

Waste disposal protocols must be in place in the Chemical Hygiene Plan (Occupational Safety and Health Administration [OSHA] Laboratory Standard 29 CFR 1910.1450) and/or HazCom Safety Plan (OSHA Hazard Communication Standard 29 CFR 1910.1200), along with employee training before potentially hazardous materials are purchased. Below is a recommended list of waste disposal protocols designed for science instructional spaces and related areas.

1.    Segregating Waste
•    Different types of waste (e.g., chemical, biological, physical) need to be separated once generated using separate appropriate containers or designated areas.
•    All waste containers must be appropriately labeled for each type of waste to avoid contamination and ensure proper disposal.

2.    Chemical Waste
•    Chemical waste should be placed in appropriate containers and labeled with the type of waste and its hazards. Consult the Safety Data Sheet or other resources for specific types of containers required for specific chemicals. 
•    Unused or excess chemicals should not be disposed of in the sink unless in compliance with local regulations or state regulations and approved by the laboratory instructor/chemical hygiene officer.
•    Chemical waste inappropriate for sink disposal must be labelled and stored in a designated and secure storage area and disposed of according to hazardous waste disposal regulations.
•    Never mix chemicals unless specifically instructed in a procedure, and incompatible chemicals should be stored separately to prevent reactions. Chemical products can potentially become reactants in some instances, which can present a real potential hazard with high health and safety risks.

3.    Biological Waste
•    Biological waste (e.g., bacterial cultures, preserved specimens, and other contaminated materials) must be collected in biohazard bags or containers.
•    Sharps, such as needles and broken glassware, that are contaminated with biological materials should be disposed of in puncture-resistant containers.
•    Biological waste needs to be autoclaved or treated with appropriate disinfectants before disposal to inactivate any pathogenic organisms.
•    Disposal of biological waste must comply with local/state regulations and guidelines for biohazardous waste management.

4.    Physical Waste
•    Sharp Objects. Laboratory equipment such as needles, scalpels, broken glassware, and razor blades can cause cuts, punctures, or lacerations if mishandled. Make sure they are appropriately discarded in labeled containers, preventing direct exposure to sharps. 
•    High-Temperature Materials. Bunsen burners, hot plates, heating mantles, and other heating devices can cause burns or fires if not cooled prior to disposal.
•    High Pressure Systems. Pressurized gas cylinders and other high-pressure systems pose risks of explosion or rupture if not depressurized prior to disposal.
•    Electrical Hazards. Electrical equipment such as power sources, batteries, and so on can cause electric shock or fires if damaged. These must be neutralized prior to disposal.
•    If radioactive materials are used in experiments, radioactive waste should be handled and disposed of according to specific regulations and guidelines.
•    Radioactive waste should be stored in designated containers labeled with appropriate warnings and disposed of through authorized channels.

5.    General Waste Disposal
•    Non-hazardous waste (e.g., paper towels, gloves, and other non-contaminated materials) can normally be disposed of in regular waste bins.
•    Empty chemical containers must be rinsed and cleaned thoroughly prior to disposal to remove any remaining residues. Make sure the chemical residue will not react with water before using this method.

6.    Emergency Spill Protocol
•    In the event of a chemical or biological spill, students need to immediately notify their teacher and follow established spill response procedures.
•    Spill kits containing absorbent materials, gloves, goggles, and other necessary equipment should be readily available for quick cleanup in each science instructional space and associated areas.

7.    Recordkeeping
•    Appropriate records must be maintained, documenting waste disposal information, including the types and quantities of waste generated, as well as the disposal methods used.
•    Any safety incidents or accidents related to waste disposal must be documented, investigated, and reported as necessary.

8.    Training and Education
•    Students, teachers, and custodians must receive training on waste disposal protocols, including proper segregation, handling, and disposal of different types of waste before using biological, chemical, or physical hazards.
•    The Chemical Hygiene Plan must be updated annually relative to appropriate chemical waste procedure protocols. The department safety plan must also be updated annually relative to appropriate biological, chemical, and physical waste procedure protocols.
•    Regular refresher training sessions must be conducted to reinforce safety practices and ensure compliance with waste disposal regulations.

In following waste disposal protocols, those working and learning in middle and high school instructional spaces and associated areas can minimize environmental impact, protect the health and safety of students and staff, and comply with legal safety standards and better professional safety practices. If biological, chemical, or physical waste present a real problem that can’t safely be addressed by school employees, there are commercial hazard waste companies that specialize in their removal.  

Follow Dr. Ken Roy five days a week on X—@drroysafersci—for current safety updates.