University Safety and Assurances

Storage Rules for Flammable Liquids


General Information:

According to the National Fire Protection Association NFPA 30: "Flammable and Combustible Liquids Code", which applies to office, educational, and institutional occupancies and day care centers storage shall be limited to that required for the operation of office equipment, maintenance, demonstration and laboratory work.

These four rules for indoor storage of flammable and combustible liquids in Educational and Institutional Occupancies have been established by the National Fire Protection Association (NFPA):

  • Containers of Class I liquids that are stored outside of an inside liquid storage area shall not exceed a capacity of 5 L (1.3 gallons)

    Exception: Safety can shall be permitted up to a l0 L (2.6 gallon) capacity.

  • The combined volume of Class I and Class II liquids stored in a single fire area outside of a storage cabinet or an inside storage area not stored in safety cans shall not exceed 38 L (10 gallons)
  • The combined volume of Class I and Class II liquids stored in a single fire area in safety cans outside of an inside liquid storage area of storage cabinet shall not exceed 95 L (25 gallons)
  • The volume of Class IIIA liquids stored outside of an inside liquid storage area or storage cabinet shall not exceed 230 L (60 gallons)

Storage for industrial and education laboratory work shall comply with NFPA 45, "Standard on Fire Protection for Laboratories Using Chemicals."

Chemical Refrigerators:

Ordinary domestic refrigerators and freezers must not be used for storing flammable liquids due to exposure to electrical components (light bulbs, switches, contacts and motors) that can become potential ignition sources. These ignition sources may initiate a fire or an explosion if flammable vapors are present. Refrigerators and freezers for storing flammable liquids and/or temperature sensitive chemicals such as peroxides or epoxies must be designed, constructed and approved for that purpose. Domestic refrigerator/freezers as well as units that have been modified to remove spark sources are not acceptable.

  • Refrigerators must be labeled on the exterior: CAUTION – FOR CHEMICAL STORAGE ONLY; DO NOT STORE FOOD OR BEVERAGES IN THIS REFRIGERATOR. Labels may be fabricated by users provided the labels are legible and securely affixed to the refrigerator.
  • Refrigerators used for food storage in or near work areas (shops and labs) must be labeled with words to the effect of: NOTICE – FOOD MAY BE STORED IN THIS REFRIGERATOR. DO NOT STORE CHEMICALS. Refrigerators used for food and beverage storage that are located in lunch rooms and office buildings, where there is no shop or laboratory type chemical use, do not require any postings.

Flammability Classifications for Commonly Used Chemicals:

Class IA

Class IB

Class IC

Dimethyl Sulfide Acetone Ethylene Glycol Diethyl Ether
Ethylene Oxide Acrylonitrile Ethylene Glycol Isopropyl Ether
Ethyl Mercaptan Ethyl Acetate Hydrazine
Hydrogen Cyanide Ethyl Alcohol (Ethanol) High Flash V.M.&P. Naphtha
Pentane Ethylene Dichloride Paraldehyde
Petroleum Ether* Ethyl Ether Styrene
Propylene Oxide Heptane Xylenes
Vinyl Chloride Hexane Butyl Alcohol
Acetaldehyde Isopropanol Butyl Aceylate 
2-Butyne (Methyl Alcohol) Methanol M-Xylene
2-Chloropropane Methyl Ethyl Ketone O-Xylene
Dichlorosilane Methyl Isobutyl Ketone P-Xylene
Methyl Ethel Ether Methyl Methacrylate Amyl Alacohol
Methyl Formate Petroleum Ether* Amyl Bromide
Methyl Mercaptan V.M.&P Naphtha Butyl Nitrate
Cimethyl Sulfide Pyridine Chlorobenzene
Ethyl Amine Tetrahydrofuran Cumene
Ethyl Chloride Toluene Cyclohexanone
Ethyl Nitrite p-Dioxane Dibutyl Ether
Furan Ethyl Nitrate Hexylamine
Hydrocyanic Acid Methyl Isobutyl Ketone Isoamyl Acetate
Isoprene Methyl Methacrylate Isobutyl Alcohol
1, 3 Pentadiene Octane Nitromethane
Trichlorosilane Triethylamine Turpentine

* May fall into Class IA or IB, depending on the Boiling Point of the mixture

Source: Fire Protection Guide to Hazardous Materials, 10th edition, NFPA, 1991.

Each petroleum product (oil, antifreeze, WD40, etc.) should be categorized and kept under these limits. Some simpler rules of thumb may be easier to remember and follow:

  • Class I liquids shall not be handled or used in basements.
  • No flammable liquid storage in mechanical rooms.
  • No more than one drum of combustible liquids in one room (one drum of oil or one drum of antifreeze).
  • Minimize the amount and time that paint is stored in mechanical rooms, unless stored in flammable storage cabinets.