Flammable or combustible liquids are stored and used in almost all businesses, whether they are manufacturing, processing or commercial institutions. Regulations governing the storage and handling of these liquids appear in municipal, county and state fire codes across the country.

Generally these codes are based on existing model codes, such as The International Fire Code, the Uniform Fire Code™ NFPA 1, or The Flammable and Combustible Liquids Code: NFPA 30. OSHA regulations are similar to NFPA 30.

While the codes are similar in language, differences do occur. The reader is advised to make certain his practices and procedures are acceptable to the authority having jurisdiction (AHJ) in his facility. This "authority" may be your state or local fire marshal, insurance inspector, your corporate safety director or another individual in a position of responsibility.

When the 2008 edition of NFPA 30 was released, the fire protection community was presented with a host of new requirements. The new regulations are intended to be consistent with the Uniform Fire Code™ NFPA 1 and NFPA® 5000 Building Construction and Safety Code®. The concepts of maximum allowable quantities, control areas and protection levels have all been introduced.

Use of approved equipment, such as safety storage cabinets, not only helps companies meet these regulations, it also reduces the danger flammable liquids present.

Why use cabinets?

"Approved" equipment represents products tested by an independent, third-party testing organization such as FM Global or Underwriters Laboratories (UL). Approved cabinets provide a heat-resistant enclosure that helps protect both personnel and property in the event of a fire. Cabinets also help you identify, organize and segregate dangerous liquids. They may be located near points of use, saving time and effort by eliminating frequent trips to a central storage room. Safety cabinets improve security and protect against unauthorized withdrawal. Finally, in general occupancies, NFPA 30-2008 doubles the MAQ (maximum allowable quantity) of flammables and combustibles per control area when stored in approved cabinets.

NFPA 30 describes a flammable liquid storage cabinet as follows:1

9.5.3 Storage cabinets that meet at least one of the following sets of requirements shall be acceptable for storage of liquids:

(1) Storage cabinets designed and constructed to limit the internal temperature at the center of the cabinet and 1 in. (25 mm) from the top of the cabinet to not more than 325°F (163°C), when subjected to a 10-minute fire test that simulates the fire exposure of the standard time-temperature curve specified in NFPA 251, Standard Methods of Tests of Fire Resistance of Building Construction and Materials, shall be acceptable. All joints and seams shall remain tight and the door shall remain securely closed during the test.

(2) Metal storage cabinets constructed in the following manner shall be acceptable:
(a) The bottom, top, door and sides of the cabinet shall be at least No. 18 gauge sheet steel and shall be double-walled, with 1-1/2 in. (38 mm) air space.
(b) Joints shall be riveted, welded or made tight by some equally effective means.
(c) The door shall be provided with a three-point latch arrangement, and the door sill shall be raised at least 2 in. (50 mm) above the bottom of the cabinet to retain spilled liquid within the cabinet.
(3) Wooden cabinets constructed in the following manner shall be acceptable:
(a) The bottom, sides and top shall be constructed of exterior grade plywood that is at least 1 in. (25 mm) thick and of a type that will not break down or delaminate under fire conditions.
(b) All joints shall be rabbeted and shall be fastened in two directions with wood screws.
(c) Where more than one door is used, there shall be a rabbeted overlap of not less than 1 in. (25 mm).
(d) Doors shall be equipped with a means of latching, and hinges shall be constructed and mounted in such a manner as to not lose their holding capacity when subjected to fire exposure.
(e) A raised sill or pan capable of containing a 2 in. (50 mm) depth of liquid shall be provided at the bottom of the cabinet to retain spilled liquid within the cabinet.
(4) Listed storage cabinets that have been constructed and tested in accordance with 9.5.3 (1) shall be acceptable.

9.5.4* Storage cabinets shall not be required by this code to be ventilated for fire protection purposes. If not ventilated, storage cabinet vent openings shall be sealed with the bungs supplied with the cabinet or with bungs specified by the cabinet manufacturer. If ventilated for any reason, the storage cabinet vent openings shall be ducted directly to outdoors in such a manner that will not compromise the specified performance of the cabinet and in a manner that is acceptable to the authority having jurisdiction.

9.5.5 Storage cabinets must be marked in lettering that is a least 2 in. (50 mm) high as follows: WARNING: FLAMMABLE - KEEP FIRE AWAY

Beyond compliance

Some cabinets incorporate safety features that exceed NFPA 30 requirements. For example, cabinets may include dual vents to meet the requirements of some local authorities and/or corporate policy. Other safety features are reflective labels that can be seen easily with a flashlight in the event of a power failure or smoky conditions, or a grounding lug on the side of the cabinet to allow for proper bonding and grounding when appropriate. To help protect against unauthorized use of flammable contents, a padlock hasp designed into the handle can offer an added measure of security.

Beyond choosing a cabinet that meets NFPA and OSHA requirements and carries FM approval, other factors must be considered.

Consider the chemical

It is important to identify and inventory all chemicals to be stored. A review of the material safety data sheet (MSDS) will determine the characteristics and recommended storage practices. To avoid generating toxic explosions and to prevent fires, it is critical to segregate incompatible chemicals. Chemical labeling and training is covered under the Hazard Communications Standard and the "Right-To-Know" Act.

Determine how a chemical relates to the construction material of the cabinet itself. Cabinets constructed of steel are suitable for flammable liquids. For non-flammable acids and other corrosive liquids, the construction material should be polyethylene or wood.

Choosing the appropriate color also helps organize and segregate different types of liquids. While regulatory codes do not mandate a specific color, industry customarily observes the following:
  • Yellow – Flammables
  • Red – Combustibles
  • Blue – Corrosives
  • Green – Pesticides and Insecticides
Safety cabinet doors may be manual-close or self-closing. Economical manual-close styles permit doors to open a full 180 degrees and require the user to physically shut the doors. Self-close, self-indexing doors incorporate a mechanism that automatically shuts the doors upon release. Fusible links hold the doors open during use, but if inadvertently left open, will melt at 165°F (74°C) in the event of a fire, automatically closing the doors.

Choose a cabinet that is acceptable to the "authority" in your facility, in an appropriate material, size, style and color that meets your need.