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April 2005: Aerosols

Aerosols are grouped into Levels 1, 2 and 3. Level 1 aerosols are predominately water-based (a good example is shaving cream) and their fire hazard is about the same as ordinary combustible goods in cartons. Level 2 aerosols are predominately water miscible flammable/combustible liquids; they produced intense fires, and ruptured cans are propelled. Though the fire can spread, the relative small amount of water miscible liquid is quickly diluted and extinguished by sprinklers. Level 3 aerosols present the greatest challenge. They are predominately insoluble flammable/combustible liquids. There fires are just a serious as Level 2 aerosols, with the added hazard that a ruptured can releases flammable/combustible liquids that are not easily diluted or extinguished by sprinklers.

The overall fire hazard of an aerosol product is a function of the chemical heat of combustion. Testing has shown that aerosols can have a mixture of the three basic liquids (water, soluble flammable liquids and insoluble flammable liquids) with the classification in part based upon the percentage of each material. The actual Level of the aerosol can be determined by testing or through a determination of the percentage of each basic liquid.

Level 1 aerosols can be protected as Class 3 commodities in both palletized and rack storage.

Protection of Level 2 and 3 aerosols need to be protected through sprinklers and mostly through segregation of the aerosols from other storage (the propelled cans create multiple fires). Examples include:

Small storage quantities can be segregated into small, low-cost metal frame or concrete block buildings outside a warehouse, or to store products in trailers away from the buildings, or under covered docks external to the warehouse well away from any openings to the warehouse.

At mercantile locations, products in selling areas do not present an unusual fire hazard in sprinklered buildings if they are not inside combustible packaging. In the storerooms these products can be relocated to small noncombustible detached buildings, located in small sprinklered cut-off rooms, or, removing the cans from the shipping cartons and store in noncombustible bins or shopping carts well away from other combustible storage.

Shipping/receiving areas within warehouses should be located as close as to the designated aerosol storage area as possible. This will reduce the chance of transported pallet loads of aerosols through the general warehouse area. Storage should be limited in height.

Warehousing of Level 2 and 3 aerosols should be accomplished by segregation of these products from other storage. Full height walls can accomplish segregation. One-hour rated gypsum board can be used, but needs to be faced with at least 22 gauge metal to protect against aerosol can impacts. Chain link fencing can also be used, with adequate separation of storage from the fence on both sides.

Except in cases where storage is placed in low-cost, detached structures, adequate sprinkler protection is needed based upon the Level of the aerosol and how it is stored (palletized, shelves or racks).

Risk Logic can provide assistance in helping to determine the degree of hazard of the aerosols as well as the different protection schemes available based on how and where you wish to have the aerosols.