For a fire to occur you must have all three sides of the fire triangle present, namely
Eliminating any of these will make it impossible to start a fire or extinguish one that is already going.
The hazards of fire include:
There are many different types of substance that can act as a fuel. They are arranged into different classes:
Class A – solids (e.g. paper, wood, plastic);
Class B – flammable liquids (e.g. paraffin, petrol, oil);
Class C – flammable gases (e.g. propane, butane, methane);
Class D – metals (e.g. aluminium, magnesium, titanium);
Class E – Fires involving electrical apparatus;
Class F – Cooking oil and fat.
Also, oxidising agents, whilst not necessarily fuels in their own right can cause other substances to catch fire, possibly without oxygen being present.
The following can act as sources of ignition, causing a fire to start if there is fuel and oxygen present:
Fire can spread, causing more fire and subsequently more harm and damage. There are three main mechanisms that allow fire to spread. They are:
The main ways of preventing fire are by controlling fuels and ignition sources. In particular using suitable equipment for storing and transporting highly flammable materials. Also, selecting equipment for use in flammable hazardous areas that will not act as an ignition source.
Oxidising agents need to be handled carefully and kept away from flammable materials.
The possibility of arson must be considered, and keeping sites secure and free from rubbish and other flammable items is important.
Fires can be extinguished by eliminating any side of the fire triangle. This usually involves cooling, creating a barrier between fuel and oxygen, using a chemical that interferes with the fire process, or replacing oxygen with another non-flammable gas. Types of extinguishing device include:
A British Standard (BS 5306-3:2009) sets out good practice for the commissioning and maintenance of portable fire extinguishers. It requires that new extinguishers are properly and comprehensively commissioned at the place they are to be installed by a Competent Person (which is defined in the standard). All extinguishers should be subject to weekly checks, monthly visual inspections, an annual basic service and an extended service and overhaul at specified frequencies.
People need to know there is a fire so that they can escape. Options for detection include:
Factors that affect ease of escape from fire (and other emergency situations) include:
As a general rule lifts (elevators) should not be used for evacuation. Also, it is necessary to make special arrangements for disabled people including those with physical disabilities that affect their mobility, visual disabilities and the deaf who cannot hear alarms and instructions.
From 1 October 2006 the Regulatory Reform (Fire Safety) Order 2005 is law. The cornerstone of the regulations is fire risk assessment. Through this the following need to be considered:
Emphasis is on the employer being responsible for managing risks from fire. To achieve this they need to have competence to assess and control the risks. A series of guides has been published covering different types of establishment including offices and shops, factories and workshops, residential care and educational premises.
Reference – Department for Communities and Local Government website at
http://www.communities.gov.uk/fire/firesafety/firesafetylaw/
For places of work that manufacture, store, process or use dangerous substances (as defined), the Dangerous Substances and Explosive Atmosphere Regulations 2002 (DSEAR) apply. The definition includes:
The regulations require employers to make a suitable and sufficient assessment of risks to his employees which arise from the substance. This shall include the potential for a flammable or explosion atmosphere to occur and the likelihood and control of potential ignition sources.
Reference – Dangerous substances and explosive atmospheres ACOP available free at http://www.hse.gov.uk/pubns/priced/l138.pdf
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