Precautions against fire

An installation designed and constructed to the requirements of BS 7671, described in Chapter 10, is not a fire hazard if it is properly maintained. To minimise the danger of ignition from the several possible causes listed in the subheadings, the relevant design precautions are described. 

Cables should be of adequate rating for the load, having regard to environmental conditions, e.g. under or in thermal insulation or in hot environments. 

Cables should be protected by correctly rated excess current protective 

Apparatus such as motors which may be subject to overloading should be provided with their own excess current protection and, where necessary, 

Ensure that circuit breakers and fuses are adequately rated for the potential fault level and can safely and rapidly interrupt the short circuit current. 

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Health and Safety Factors. Both pyromellitic acid and its dianhydride irritate skin, eyes, and mucous membranes, and they cause skin sensitization (156). When it comes in contact with moist tissue the dianhydride converts to the acid. Direct contact with should be avoided and protective clothing should be worn in areas where it is used. The LD q for intergastric administration in rats is 2.2—2.6 g/kg (157). In 6-mo experiments, the maximum nontoxic dose was 0.07 mg/kg/d, and it affected the fiver, kidney, and reproductive tract. Precautions against fire and dust explosions as explained in the terephthafic acid section should be foUowed. 

Ensure all precautions against fire or explosion are taken during carriage. 

While insensitive to shock, the mixture is a fire hazard and normal precautions against fire should be observed. If 50 pounds or more is being used in one charge, anyone within a few hundred yards is in danger of being struck by flying debris. 

The blowing agent can be a hydrocarbon (pentane, for example), which is easily flammable, and precautions against fire must be taken at all the stages of transport, handling, storage, manufacture... 

Caution Since carbon disulfide is highly flammable and hydrogen sulfide highly toxic, this reaction should be carried out in a hood, with due precaution against fire. It is also recommended that tetracyanoethylene not be allowed to come into contact with the skin. 

Caution Sodium hydride causes severe burns if brought into contact with the skin and, in the dry state, is pyrophoric. Since hydrogen is evolved during the course of the reaction, the necessary precautions against fire and explosion should be taken. 

In preparing these papers, every precaution against fire should be taken, and their preparation in the shop or house should not be thought of. In making the solutions, etc, where heat is necessary, the water bath should invariably be used. 

Consequently, manufacturers handling such fine powders must take special precautions against fires and explosions. 

CP 3 Chapter IV 1948 Precautions against fire CP 402 Fire fighting installations and equipment CP 402 201 1952 Sprinkler systems... 

Of great importance are the sections on hazardous activities, admittance to dangerous areas, consumption of alcohol, testing of equipment and machinery, and precautions against fire and explosions. 

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