Minimising fire risks at chemical storage facilities: Basis for the guidelines for safety engineers

The report addresses fire safety engineering problems of chemical storage facilities. The methodology of the guidelines is based on the ISO/TC 92/SC4 Fire Safety Engineering -documents. The basic elements of fire safety design of a chemical warehouse are described: construction design, model fires and fire simulation, storage and packaging, preventive and protective systems, building location and safety distances. Concerning the design of the warehouse construction, the following items are discussed: compartmentation and structures, escape routes, smoke ventilation and retention of spills and fire fighting water. Design fires and fire development are discussed with an emphasis on the fire simulation models. The influence of the storage layout and packaging on the fire spread and the consequences of fire are discussed, including the effects of the size and separation of the stacks, the physical properties of the packaging and the nature of the stored materials, as well the mechanisms in which packaging can contribute to the fire. The discussion on the preventive and protective systems includes treatise on alarms and fire detection, sprinklers and other automated means of extinction. Also some conclusions derived from the TOXFIRE project on the influence of extinction on chemical fires are presented. An assessment of safety of the chemical storage facilities includes a brief discussion on the warehouse location, orientation and site access. The question of safety distances is handled in more details by presenting a four-step procedure as a guide to assess low risk distances. The ingredients of this procedure are 1) the survival fraction, 2) toxicity values, 3) fire scenario, dispersion and weather situation, and 4) the exposure time.