Storage and Use of Flammable and Combustible Liquids
This section has been reviewed and updated as needed: June 2014
It is the policy of the University to use the recommendations contained in the National Fire Protection Association (NFPA) Codes as minimum guidelines to acceptable practices on Campus. A number of the NFPA Codes have been incorporated into the Occupational Safety and Health Act (OSHA) Standards, the North Carolina State Building Code, or are mandated as a condition of insurance coverage by the North Carolina Department of Insurance. Questions regarding the applicability of specific NFPA Codes should be directed to the University Fire Marshal.
The purpose of this policy statement is to list the basic standards for the storage and use of flammable and combustible liquids applicable to Campus operations. The standards listed here are by no means comprehensive but represent those cited most frequently during inspections of Campus facilities.
- Laboratory Unit
- A laboratory unit is defined as a room, or suite of rooms, separated from adjacent areas by walls and doors having at least a one hour fire rating.
- Flash Point
- The minimum temperature at which a liquid gives off vapor in sufficient concentration to form an ignitable mixture in air.
- Flammable Liquids
- A flammable liquid is any liquid having a flash point below 100°F (37.8°C). Flammable liquids are also known as Class I liquids and subdivided according to flash point and boiling point as indicated in the table below.
- Combustible Liquids
- A combustible liquid is any liquid having a flash point at or above 100°F, and is known as a Class II or III liquid as indicated in the following table.
- Flammables Combustibles
- IA IB IC II III
- Flash point <73°F <73°F 73°F – 100°F 100°F – 140°F >140°F
- Boiling Point <100°F 100°F> <100°F
Maximum Container Size for Point of Use Storage
The potential fire hazard depends on the flash point and the quantity of liquid being used. The following table gives the maximum size container allowed for each class of liquid.
- Container Type IA IB IC II III
- Glass 1 pt. 1 qt. 1 qt. 1 gal. 1 gal.
- Metal or Approved Plastic 1 gal. 5 gal. 5 gal. 5 gal. 5 gal.
- Safety Cans 2 gal. 5 gal. 5 gal. 5 gal. 5 gal.
The potential fire hazard also depends on the total quantity of flammable and combustible liquids present within a containment unit and the type of containers in which the liquids are stored. The maximum quantity allowed per unit is as follows:
- Shelf or open storage/use:
- Glass, plastic, or cans: 10 gallons
- Safety cans: 25 gallons
- Approved storage cabinets (maximum 2 per lab unit)
- Class: 30 gallons
- Class I & II & III: 60 gallons
- Inside Storage Room (meeting NFPA Code recommendations)
- with sprinkler: 4 10 gal/ft2
- without sprinkler: 2 4 gal/ft2
It should be emphasized that quantity of flammables on hand must be kept to a minimum and that only in unusual circumstances will the maximum quantities be permitted.
The following guidelines were adopted by the University on the recommendation of the Deputy Commissioner of Insurance.
- If a one gallon quantity of one specific liquid represents more than a thirty day supply of a Class IA or IB flammable, one pint (IA) or one quart (IB) shall be used.
- Multiple cans and/or bottles of any one specific flammable will not be permitted in a laboratory in open storage or storage cabinet if it represents more than a 30 day supply of that flammable.
- Quantities stored in inside storage rooms shall not exceed a 90 day supply for that building.
- Deviations from these guidelines may be granted in exceptional cases following approval by the University Fire Marshal.
NOTE: Fisher Scientific will set up orders for weekly or more frequent deliveries of goods ordered in volume, thus maintaining the advantage of lower prices for volume orders. However, it will be the responsibility of the laboratory supervisor to see that the weekly and maximum amounts are not exceeded.
Gasoline must be stored and transported on campus in safety cans. The use of safety cans in laboratories is encouraged. Class I liquids shall not be transferred between metal containers unless the containers are electrically interconnected by direct bonding or by indirect bonding through a common ground. The maximum impedance of the bond shall not exceed 6 ohms.
Storage cabinets constructed to NFPA standards should be used when required by quantity limits. Storage cabinets are not permitted in hallways.
Inside Storage Rooms
A central storage room is preferable to storage cabinets in each laboratory. This central storage alternative should be considered especially by departments and schools which have centralized supply rooms.
Flammable liquids must not be stored in domestic type refrigerators. Domestic type refrigerators should not be purchased for laboratory use, even if flammable storage is not contemplated, since future research needs may require the use of flammables. Safety refrigerators, which have the electrical contacts (door switch, light, thermostat, etc.) removed or exteriorized, are recommended for laboratory use. “Explosion Proof” refrigerators are not recommended except in unusual circumstances, such as in an inside storage room (for flammables) or in potentially hazardous atmospheres.
Bunsen burners and other open flames must not be used in the area where flammable liquids are being used. The area must be posted “NO SMOKING” and containers are to be labeled “DANGER FLAMMABLE – KEEP AWAY FROM HEAT, SPARKS, AND OPEN FLAMES. KEEP CLOSED WHEN NOT IN USE.”
Variations from these guidelines may be granted when chemical purity or other considerations warrant. For further information, contact the University Fire Marshal (919-962-5507).