Plastics Storage

Hazard picture

Plastics release substantially more heat energy per kilogram in a fire than paper, wood or textiles, since they are made of petroleum-based polymers with a high carbon content. Foamed products such as polystyrene or polyurethane foam further increase the surface area exposed to the flame through their porous structure, so a fire spreads considerably faster than with compact forms of the same weight. Unpackaged plastic parts or those stored in open wire baskets amplify this effect further, since the packaging no longer provides any dampening effect.

Protection measures

Recognised commodity classifications distinguish between expanded (foamed) and unexpanded plastics as well as between exposed and carton-enclosed storage, since each combination requires its own sprinkler design. If a sprinkler system sized for standard commodities is later used for plastics storage without adjusting the design basis, fire protection is generally inadequate. Additional measures such as in-rack sprinklers, reduced stack heights or limiting storage area per fire compartment compensate for the higher fire load.

Insurance relevance

Because a shift in stored commodity from metal or paper products to plastic items can substantially raise the hazard class of an area without any visible change to the building, verifying the actual commodity mix is one of the most important points of any risk survey at storage operations. A sprinkler design left unadjusted after such a commodity change is among the most frequent causes of underestimated major losses in warehouse logistics.