It is usually referred to, as the amount of heat that can be generated by the materials in an enclosed area, such as a room or compartment. The fire load of that area can be used to quantify the potential severity of a fire in that specific area and so it is an important concept in fire safety, firefighting, and construction. The room's fire load is quantified as the amount of heat that would be generated per unit of area in the room if all the combustible materials in that room were burned. The room's fire load is calculated by adding up all the fuel present and dividing it by the area of the room or compartment. E3.1 Summary In this section we have covered: Sources of fuel, oxygen, and ignition sources • Common sources of ignition of accidental fires • Sources of fuel • Sources of oxygen • Factors influencing the severity and likelihood of an arson attack • Fire and explosion risks from the use, storage, and transport of flammable materials within the workplace • The concept of fire load 3.2 Appropriate control measures to minimise fire and explosion risks Assessment criteria: 3.2: Outline the principles of explosion and explosive combustion and the controls that can be put in place. Control of sources of ignition Suitable explosion protected electrical equipment for use in flammable and explosive atmospheres Intrinsically, safety of electrical equipment should be in place. Intrinsic safety is a protection technique for safe operation of all electrical equipment in hazardous areas (such as flammable and explosive atmospheres) by limiting the energy available for ignition. Electrical equipment that is to be installed in these areas must be designed and tested so it does not initiate an explosion by the means of contacts arcing, or high surface temperatures from the equipment. For example, a simple task of switching a light switch on, can emit a small harmless spark, but if this was done in a flammable or explosive atmosphere, then this spark could ignite flammable vapours in the air that may be present. Electrical equipment should therefore be designed to contain any explosion within the equipment itself or be designed not to produce any sparks that can cause an explosion. Electrical equipment should be minimised or kept out of the area altogether. Improvements to the area may allow for additional ventilation systems being installed and areas being classified as zones. The zone can then determine the controls that are needed because of potential sources of ignition that may be present in that area. International Electric Commission (IEC) standard 60079-18:2014 gives the specific requirements for the construction, testing and marking of electrical equipment, parts of electrical equipment and Ex components with the type of protection encapsulation “m” intended for use in explosive gas atmospheres or explosive dust atmospheres.
©SHEilds – All rights reserved FCV3 JUN 2021
Page 8 of 24
Made with FlippingBook Digital Publishing Software