The quantities of chemicals that are stored within
a laboratory should be minimized, as specified by NFPA 45 and OSHA.
Many authorities recommend that the NFPA guidelines for maximum
quantities and sizes of containers should be reduced to one-half or
even one-third of the recommended values.
Bulk quantities of chemicals (i.e., larger than
one-gallon) must be stored in a separate storage area. Transfer of
flammable liquid from 5 gallon or larger metal containers may not be
done in the laboratory.
Chemicals must be stored at an appropriate
temperature and humidity level. This can be especially problematic in
hot, humid climates. As a rule, chemicals should not be stored near
heat sources, such as steam pipes or laboratory ovens. Chemicals
should never be stored in direct sunlight.
Chemicals should be dated when received and when
opened. If the chemical is one that degrades in quality or becomes
unsafe after prolonged storage, the shelf-life expiration date should
also be included.
Visual inspection of the material and its container
should be conducted routinely. Indications for disposal include:
- cloudiness in liquids
- material changing color
- evidence of liquids in solids or solids in liquids
- "puddling" of material around outside of container
- pressure build-up within bottle
- obvious deterioration of container
Chemicals should not be routinely stored on the
benchtops. In such locations they are unprotected from exposure and
participation in a fire situation and are also more readily knocked
over. Each chemical should have a specific storage area and be
returned there after use. Large quantities of flammable materials
should not be stored in the laboratory. Only the amounts needed should
be kept on benchtops, the remainder should be kept in flammable
Laboratory shelves should have a raised lip along
the outer edge to prevent containers from falling. Never allow the
container to hang off the edge of the shelf! Liquid or corrosive
chemicals should never be stored on shelves above eye-level. Glass
containers should not touch each other on the shelves. Secondary
containers or trays should be used for chemical storage whenever
possible to minimize the flow of material should a spill or rupture
occur. Round bottom flasks should always be supported properly in cork
rings or by other means to keep them from tipping.
Adequate security must be provided so that
unauthorized personnel do not have access to hazardous materials.
Chemicals must never be stored on the floor, not
Chemicals that are no longer to be used for
research purposes should be properly disposed of or given to another
research group that has a use for it.
Flammable materials must never be stored in
domestic-type refrigerators. Only explosion-proof or flammable
material refrigerators should be used for storage of these chemicals
within a laboratory environment.
All containers stored within the refrigerator
should be tightly capped to keep vapors from interacting with each
other and to alleviate "smell" problems. Flasks with cork,
rubber or glass stoppers should be avoided because of the potential
for leaking. All containers stored in the refrigerator must be
Inventory the materials in your refrigerator
frequently to avoid overcrowding with materials that have long since
been forgotten. Also make it a point to defrost your refrigerator
occasionally so that chemicals do not become trapped in unique ice
Before flammable materials are stored in a
refrigerator, it should be determined if keeping the material chilled
will serve any purpose. No benefit is derived from refrigerating a
chemical that has a flash point below the temperature of the
refrigerator. Never store peroxide formers (i.e., ether) in a
Fume hoods should not be used as general storage
areas for chemicals. This may seriously impair the ventilating
capacity of the hood.
Gas cylinders must be securely strapped to a
permanent structure (wall, lab bench, etc.). When they are not in use
they should be capped off.
On termination, graduation or transfer of any
laboratory personnel, all hazardous materials must be properly
disposed of, or arrangements made to transfer them to the laboratory