What procedures should science teachers use to safely close down high school science laboratories and classroom instructional spaces before summer vacation? Closing laboratories and classroom instructional spaces for summer doesn’t just mean tidying up; it should be a well-planned process that reduces fire risk and chemical instability and prevents unauthorized access over the several months of summer vacation, in addition to other components. An appropriate process needs to align with the Occupational Safety and Health Administration (OSHA) Laboratory Standard (29 CFR 1910.1450), the OSHA Hazard Communication Standard (29 CFR 1910.1200), and guidance from the National Science Teaching Association and the American Chemical Society. 

Teachers need to address several major areas in practical, school-ready safety procedures.

Chemical Inventory and Hazard and Risk Review

First, conduct a full chemical inventory. The following items need to be reviewed and either removed or flagged:

• expired, degraded, or unknown chemicals
• peroxide-forming chemicals (e.g., ethers) nearing expiration
• unstable or shock-sensitive materials 

Ensure that all containers are clearly labeled (no abbreviations); are tightly sealed and in good condition; and have updated Safety Data Sheets (digital versions or hard copies in a binder). 

Chemical Storage and Segregation

Store chemicals by compatibility, not alphabetically (e.g., acids separate from bases, oxidizers away from organics, flammables in a flammable storage cabinet). Next, make sure caps are secure; secondary containment is used where appropriate; and shelving is anchored, stable, and not overloaded. Maintain proper shelving clearance from ceilings as required by local fire code and National Fire Protection Association legal safety standards (no closer than 18 inches from the ceiling, except for exterior wall storage that is allowed up to the ceiling as long as the fire sprinkler head is clear of wall shelving).

Waste Disposal

Do not leave chemical waste over the summer unless it is properly stabilized. Arrange for disposal through a licensed hazardous waste vendor for chemicals that cannot be appropriately disposed of using in-house means. Label all waste containers with their contents, hazard class, and accumulation start date. Do not store incompatible wastes together. 

Gas, Water, and Electrical Shutdown

Be sure to turn off gas valves (both bench and main line if applicable) and water to lab stations (if there is a risk of leaks). Unplug non-essential electrical equipment. Leave critical systems (e.g., refrigerators and freezers storing chemicals) powered and labeled. 

Laboratory Equipment

Clean and dry all glassware. Store sharp or fragile items safely. Remove batteries from devices if the devices will be stored long term. Cover and store microscopes and sensitive equipment. 

Refrigerators and Chemical Storage Units

Remove all food (though food should not be present in lab fridges). Ensure that any units used for chemicals are clearly labeled with “No food or drink for human consumption.” Make sure that any chemicals stored are appropriate for refrigeration (e.g., no flammables in standard fridges). Defrost refrigerators and units if needed before cleaning. 

Biological Materials

Properly dispose of bacterial cultures and preserved specimens (if degraded or no longer needed). Clean surfaces with soap and water, then disinfect surfaces and storage areas. Comply with local health regulations. 

Housekeeping and Fire Safety

Remove any clutter from benches, counters, and floors. Keep walkways, egress to exits, eyewash stations, and safety showers fully accessible. Maintain 18-inch clearance below sprinkler heads (per fire code legal safety standard and/or better professional safety practice). Take down or secure combustible decorations or paper materials. 

Safety Equipment Check

Inspect eyewash and safety showers (brief activation if allowed), fire extinguishers (check inspection tags), and fume hoods (turn off if appropriate; lower sash). Arrange to have fume hoods inspected by a certified inspector private contractor. Inspect and restock (if necessary) spill kits, first aid supplies, and personal protective equipment (e.g., gloves, safety goggles and glasses, aprons). 

Security and Access Control

Lock all chemical storage areas. Limit access to authorized personnel only. Secure doors, prep rooms, storerooms, and cabinets. Post emergency contact information for summer staff or facilities personnel. 

Documentation and Communication

Leave a summer status report that includes chemical inventory updates, known hazards, and notes on equipment that should be left running. Provide administration and facilities personnel with emergency contacts and any special instructions (e.g., Do not unplug this refrigerator, keep ventilation on, etc.).

Planning Ahead for Fall

Order needed laboratory instructional space supplies early, including chemicals that should be replaced. Document any safety concerns observed during shutdown procedures. 

Bottom Line

It is critical to prepare laboratory and classroom instructional spaces for the summer vacation, not only for the safety of employees working in the summer (e.g., custodians and maintainers) but also for any summer programs that use these instructional spaces. 

Submit questions regarding health and safety issues in science and STEM instructional spaces to Ken Roy at safersci@gmail.com. Follow Ken Roy on X: @drroysafersci.

The mission of NSTA is to transform science education to benefit all through professional learning, partnerships, and advocacy.