Good rules of thumb for chemical handling and storage in the lab

If there is anything that all laboratories have it is bottles and bottles of chemicals. Forensic laboratories are no exception. If we are not diligent in properly handling and storing these hazardous substances, problems are sure to arise. Potential problems run the gamut from minor inconvenience to life threateningly serious. Keep reading to learn how to avoid mishaps from mishandled chemicals.

Previous Safety Guys articles have laid a foundation for managing chemicals in laboratories. These covered understanding the National Fire Protection Association’s (NFPA) hazard diamond, how to decipher material safety data sheets, and constructing a proper chemical inventory for the lab. In this column we provide general safety rules of thumb for handling and storing chemicals in the laboratory.

Aside from the ubiquitous fire codes, many federal, state, and local regulations have specific requirements that affect handling and storing chemicals in labs and stockrooms. Examples include controlled substances regulated by the Drug Enforcement Agency, consumable alcohols covered by the Food and Drug Administration, radioactive substances controlled by the Nuclear Regulatory Commission, and hazardous wastes governed by the Environmental Protection Agency. Requirements range from locked storage cabinets and specific waste containers to secured access for “regulated” areas. Make sure you know which regulations apply and what the specific requirements are for all special chemicals and wastes at your facility.

A more common scenario is applicability of state and/or local building codes, which are becoming more rigorous each year. Hopefully these were identified and attended to during design and construction; but, we all know that labs evolve and change over time within the facility. And, unfortunately the state fire marshal and local codes inspectors are not shy about pointing out were we have crossed the line.

First things first: proper personal protective equipment (PPE)
Before we start grabbing bottles of chemicals and moving them around we need make sure we have the proper PPE. At a minimum this would include appropriate chemical resistant gloves and eye protection. Closed toe shoes are a definite and considered a general requirement for working in any laboratory. Use lab coats or chemical aprons when moving liquids and when required by your laboratory’s safety policy.

We have covered PPE, but before we begin re-arranging chemical containers in the laboratory there are a couple more things to organize and take note of. First, survey your surroundings and take note of any potential tripping hazards and work stations where others are busy. Make sure exits, passageways, and emergency equipment areas (i.e. eyewash and safety showers) are clear and free of stored materials. Locate and have close at hand a full spill kit with appropriate absorbent materials, neutralizing agents, clean up utensils, and waste containers. Finally, check that all chemical containers have complete labels in good condition and that safety data sheets are readily available.

Tips for safe transportation
Here are a few pointers for moving chemicals safely:

  • First, never move visibly degrading chemicals and containers. Report these to your lab supervisor.
  • Whenever transporting chemicals, place bottles in appropriate leak-proof secondary containers to protect against breakage and spillage. A good example is using a special plastic tote for carrying four-liter glass bottles of corrosives or solvents.
  • When moving multiple, large, or heavy containers use sturdy carts. Ensure the cart wheels are large enough to roll over uneven surfaces without tipping or stopping suddenly. If carts are used for secondary containment make sure the trays are liquid-tight and have sufficient lips on all four sides.
  • Do not transport chemicals during busy times such as break times, lunch periods, or class changes (for those academic forensic laboratories).
  • Use freight elevators for moving hazardous chemicals whenever possible to avoid potential incidents on crowded passenger elevators. Remember to remove gloves when pushing elevator buttons or opening doors.
  • Never leave chemicals unattended.

General guidelines for chemical storage
Safely storing chemicals in laboratories or stockrooms requires considering many health and safety factors. In particular, proper use of containers and common lab equipment is critical. Here are some general guidelines for safe chemical storage:

  • Do not store large, heavy containers or liquids on high shelves or in high cabinets. A good rule is to store these at shoulder level or below.
  • Do not store bottles on the floor unless they are in some type of secondary containment.
  • Do not store chemicals near heat sources or in direct sunlight.
  • Do not store chemicals in fume hoods. Excessive containers interfere with airflow and hood performance. Only chemicals in use should be in the hood.
  • Especially avoid storing anything on top of cabinets. This can interfere with the fire suppression system. Ensure at least 18 inches of clearance around all sprinkler heads.
  • Do not use bench tops for storage. These workspaces should only contain chemicals currently being used.
  • Do not store chemicals indefinitely. Humidity causes powders to cake or harden. Liquid chemicals evaporate. We strongly recommend all containers be dated when they arrive in the lab. Ensure all manufacturers’ expiration dates are strictly followed. Pay special attention to reactive or dangerous compounds. Dispose of all outdated, hardened, evaporated, or degraded materials promptly.
  • Do label all chemical containers fully. We recommend placing the user’s name along with the date received on each one.
  • Do provide a specific storage space for each chemical and ensure return after each use.
  • Do store volatile toxics and odoriferous chemicals in ventilated cabinets. Please check with your environmental health and safety personnel for specific guidance.
  • Do store flammable liquids in approved flammable liquid storage cabinets. Usually only a small amount of flammable liquid is allowed in the open room. Check with your local authority (e.g. fire marshal, EH&S personnel) for allowable limits.
  • Do separate all chemicals, especially liquids, according to compatible groups. Follow all precautions regarding storage of incompatible materials. Post a chemical compatibility chart in the lab and next to chemical storage rooms for reference.
  • Do use appropriate resistant secondary containers for corrosive materials. This protects the cabinets and catches any leaks or spills due to breakage.
  • Do seal containers tightly to prevent the escape of vapors.
  • Do use designated refrigerators for storing chemicals. Label these refrigerators CHEMICAL STORAGE ONLY – NO FOOD. Never store flammable liquids in a refrigerator unless it is specifically designed and approved for such storage. Use only explosion proof (spark-free) refrigerators for storing flammables.

Following these simple guidelines will get you well on the way to an efficient, organized, and safely operating laboratory. Ignore them or become cavalier in their application and you may be picking through ashes or ruble one day. Spend a few minutes going through your laboratories with this list on a regular basis and you should avoid any major incidents with chemical storage. As always, Safety First!

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Additional resources

  1.  Standard System for the Identification of the Hazards of Materials for Emergency Response, National Fire Protection Association, Publication 704.
  2. NIOSH Pocket Guide to Chemical Hazards. National Institute of Occupational Safety and Health. Publication 2005-149.
  3. The Merck Index, an encyclopedia of chemicals, drugs, and biologicals. 14th edition. Merck & Company, Inc. Rahway, N.J. 2006
  4. OSHA Hazard Communication Standard -
  5. Prudent Practices in the Laboratory: Handling and disposal of Chemicals. National Research Council. National Academy Press. Washington, D.C. Latest edition.
  6. Laboratory Safety Manual, University of Florida, Division of Environmental Health and Safety. 2003

Vince McLeod is an American Board of Industrial Hygiene Certified Industrial Hygienist and the senior IH with the University of Florida’s Environmental Health and Safety Division. He has 24 years of experience in all facets of occupational health and safety and specializes in conducting exposure assessments and health hazard evaluations.