Equipment will have to be selected to prevent it from becoming an ignition source – for example Ex protected electrical equipment. It will be necessary to evaluate the volume of substances that are present in the premises and the risk presented by a combination of all substances that are currently stored or being used on the premises. Some substances have low auto ignition temperatures – which means they can spontaneously ignite when that temperature is reached without an external ignition source. Other substances (such as white phosphorous) are pyrophoric which means that they burst into flame when exposed to air (oxygen). Arrangements for safe handling The handling and the use of dangerous substances will require the correct arrangements being put in place. The relevant information and training should be given anyone handling dangerous substances, and should include as appropriate: • The type and nature of the dangerous substance • The hazardous properties of the substance • How the substance should be stored and handled to minimise risk • PPE requirements when handling • Knowledge of any relevant handling procedures or safe systems of work
The relevant SDS’s should be available to anyone who is required to handle dangerous substances.
The likelihood that an explosive atmosphere will occur An explosive atmosphere can be defined as a mixture of dangerous substances with air, under atmospheric conditions, in the form of gases, vapours, mist or dust in which after ignition has occurred, combustion spreads to the entire unburned mixture. Parts of the workplaces may contain or have work activities that produce explosive or potentially explosive atmospheres. The likelihood of an explosive atmosphere to occur will require strict control measures being put in place, which may include areas being classified as 'Zones'. The zones will need to be protected from sources of ignition. Work activities that may present the likelihood of an explosive atmosphere to occur include, paint spraying and the handling of fine organic dust. The likelihood that ignition sources will be present and become active and effective All circumstances where the likelihood that ignition sources are present and can become active and effective, will need to be identified. The risk assessment should be able to identify areas where controls over ignition sources are needed, this should also include controls for any electrostatic discharges. Poor storage of highly flammable materials or liquids near uncontrolled ignition sources can quickly cause fire spread among the buildings structure and any combustible materials that may be in its path.
©SHEilds – All rights reserved FCV 3 JUN 2021
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