Ignition Source Control
A fire or explosion needs fuel, oxygen and an ignition source. Often the fuel (flammable vapor, gas or dust) cannot be fully removed, so controlling what could ignite it is the key to prevention.
- Industrial
- Oil & Gas
- Construction
Common ignition sources
- Open flames and hot work: welding, cutting, torches, grinding. See Hot Work Permits.
- Sparks: from tools, tool bits striking steel, electric motors, switches and plug-ins. See Non-Sparking Tools.
- Static electricity: from pouring liquids, filling containers, flowing dust, belts and walking on certain floors. See Static, Bonding & Grounding.
- Hot surfaces: exhaust pipes, heaters, boilers, lamps and bearings.
- Electrical equipment not rated for the atmosphere. See Hazardous Locations.
- Vehicles and engines: hot exhaust, unrated starters and alternators.
- Smoking and vaping materials. See Smoking & Vaping.
- Lightning, friction, chemical reactions and spontaneous heating. See Spontaneous Combustion.
- Portable electronics such as phones and radios in classified areas unless rated.
Control methods
- Eliminate the flammable atmosphere first if possible: ventilate, purge, clean or use substitute products with higher flash points. See Flammable Liquids.
- Map the area: post signs and boundaries for places with flammable atmospheres, and control entry of vehicles and equipment.
- Use rated equipment in classified areas (explosion-proof, intrinsically safe) and keep it maintained.
- Bond and ground containers, hoses, tanks and equipment when transferring flammable liquids or moving powders.
- Use non-sparking tools where needed and keep ferrous tools out of oxygen-rich or highly flammable areas as specified.
- Ban smoking, lighters and personal electronics in hazardous zones, and provide safe designated areas.
- Control vehicle access with spark arrestors or ignition-rated vehicles in hazardous areas.
- Use permits for hot work and entry, with gas testing before and during work.
- Cover hot surfaces and keep combustibles away from heat.
Checklist
- Is a flammable atmosphere possible here?
- What could ignite it? List every source nearby
- Which can be removed, isolated, rated or controlled?
- Is gas monitoring in place? See Gas Detectors
- Does everyone know the rules and emergency plan?
Standards & references
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