All flammable liquids, mixtures, emulsions, or semi-solids that have measurable flash points and fire points need to be stored in a space designed for a worst-case scenario.

According to the FM Global Property Loss Prevention Data Sheet entitled “Flammable Liquid Storage in Portable Containers,” flammable liquid storage rooms/buildings should be limited to the storage of flammable liquids. Other products may be stored in a flammable liquid room or building as long as they do not present a fire hazard greater than the liquid storage, and they do not represent a significant loss exposure if damaged in a fire.

The protection scheme for the entire storage room or building must be designed for the worst-case storage.

Partially full containers should be handled and stored like full containers. Empty containers should be immediately purged and cleaned. Empty containers that are sent away for cleaning should be stored outside the facility or in an area suitable for flammable liquid storage (e.g., cutoff room, flammable liquid cabinet).

Isolate flammable liquid storage by distance or construction so that they do not expose important buildings or facilities, and, in turn, are protected from fires originating elsewhere. The extent of isolation depends on such factors as the size of the container, the container construction type and the physical properties of the liquid.

Flammable liquid storage creates many different fire scenarios. Active fire protection systems, such as automatic sprinklers and special protection systems cannot be economically designed to cover every possible flammable liquid fire scenario.

Passive protection schemes, such as isolation, construction features and drainage, provide the last line of defense against the uncontrolled spread of a flammable liquid fire if the active protection systems fail to control the fire.

Failure to incorporate passive protection schemes into a flammable liquid storage facility significantly increases the likelihood of an out-of-control flammable liquid fire.

Protection Against Fire

FM Approved flammable liquid storage cabinets or storage buildings may be used for storage of flammable liquids. Storage buildings that meet all of the requirements of an inside cutoff room may be used inside the facility. Flammable liquid storage cabinets may be used in general purpose warehouses or other storage areas to store limited quantities of flammable liquids in containers ≤ 6.5 gallons.

Interior or exterior cutoff rooms should be located next to loading/shipping docks in warehouses to prevent the creation of a flammable liquid fire hazard along liquid transportation routes in buildings/warehouses that are not protected for the hazard. Ideally the cutoff rooms should be provided with their own shipping doors. Provide space in the cutoff rooms for staging of product before it is placed in storage or while it is waiting for shipment.

Flammable liquids with flash points above 200°F (93°C) packaged in metal containers ≤ 60 gal may be palletized in general purpose warehouses with a curb surrounding the storage area and no fire rated partition, if all of the following conditions are met:

a) The sprinkler protection is adequate for the stored liquids as well as the surrounding occupancy;

b) No high-value occupancies that are susceptible to heat, smoke or water damage are exposed;

c) The curb is designed in accordance with FM Data Sheet 7-83, “Drainage Systems for Flammable Liquids,” [sized for the largest container plus 2 in. (5.1 cm) of freeboard and a minimum of 4 in. (10.2 cm) high. Extend the curb at least 6 ft (1.8 m) beyond the storage footprint.

Construct cutoff room walls to be liquid- tight so that spilled liquids and vapors will be contained. Also design walls that are stable when exposed to a flammable liquid fire. Provide at least one outside access way for cutoff rooms, and protect necessary interior openings with a normally closed automatic closing fire door.

The fire door should be located on the storage side of the wall, and roof coverings should be approved for Class 1 internal fire resistance (see Data Sheet 1-29, “Roof Deck Securement and Above-Deck Roofing Components”) and an ASTM E108 Class A rated external fire resistance for all detached buildings or cutoff rooms.

For interior cutoff rooms that have ceilings below the main building’s roof, provide a ceiling assembly that has the same fire rating as the interior walls of the cutoff room.

Provide the following construction features for cutoff rooms and detached buildings used to store non-water miscible liquids with closed cup flash points < 200°F (93°C) packaged in plastic containers.

a) Provide masonry or concrete construction for one and two-hour fire rated walls.

b) Provide only exterior access to interior or exterior cutoff rooms. There should be no direct openings in the wall separating the main building from the cutoff room. The use of an enclosed walkway connecting the main building to the cutoff room is permitted if it is designed to prevent the flow of liquid out of the cutoff room.

c) Protect steel columns located inside detached buildings or cutoff rooms by one of the following methods or an equivalent:

i) Provide a sidewall sprinkler on the column, at the 1⁄3 to 1⁄2 elevation arranged to direct the water discharge into each web of the column. Design the sprinklers to provide 30 gpm/sprinkler (114 l/min/sprinkler). Include the flow in the over-all sprinkler system design.

ii) Provide a minimum of one hour fireproofing of the column.

Provide drainage and/or containment for cutoff rooms or buildings that store flammable liquids in containers greater than 6.5 gal (25 l). Design the drainage and/or containment to prevent the escape of burning liquid and limit the release of any liquid from the room/building.

Determine what drainage containment options or alternatives are acceptable for metal containers based on the stored liquids’ physical properties, the container size, and the existence of any unfavorable factors such as:

a) High-value exposed areas or equipment where prompt removal of spilled or burning flammable liquids is needed to minimize damage or production interruption.

b) A high frequency of occurrence due to design or layout where routine spills or fires are inherent hazards.

c) Liquid damage potential to nearby equipment.

d) Weak fire protection water supplies. Although sprinklers will eventually extinguish fires in high flash point or water soluble liquids, extinguishment may not be achieved prior to operating sprinklers over a greater area than that expected if the burning liquids were promptly drained from the area.

e) Where local conditions do not allow construction of adequate containment for the anticipated spill.

Drainage systems should be arranged to extinguish draining liquids and to prevent flammable vapors from backing up into buildings or rooms that are tied into those systems. One method of accomplishing this is the use of trapped drains.

Provide this arrangement for all buildings/ rooms with drains that are tied into a drainage system that can handle flammable/ combustible liquids regardless of the occupancy in that room/building. Also design emergency drainage systems to prevent liquid back-up from flood or surface water. FSM Source: FM Global Property Loss Prevention Data Sheet, “Flammable Liquid Storage in Portable Containers.”