Element 3 - Causes And Prevention Of Fires And Explosions Flashcards
Sources of ignition of accidental fires
Electrical appliances and installations. Lightning. Cooking. Heating and lighting. Smoking. Overheating of machinery. Spontaneous combustion. Hot work.
Sources of fuel
Paper and cardboard. Furniture, fixtures and fittings. Electrical installations - pvc. Structural materials - timber Piped gas supply. Flammable gases in cylinders. Flammable, chemicals, liquids and solvents.
Sources of oxygen
Atmospheric air - 21% by volume
Natural ventilation.
Forced ventilation Systems - air con
Oxidising agents/ materials.
Fire and explosion risks from flammable materials.
Common contributory factors are:
Operator error due to lack of awareness or training.
Hot work carried out on or close to flammable materials or flammable liquid containers.
Inadequate design or maintenance of equipment which fails.
Misuse of flammable liquids.
Inadequate control of ignition sources in inflammable liquid areas e.g. electrostatic discharge.
Allowing materials to be heated above the auto ignition temperature.
Dismantling disposing of equipment or containers containing flammable materials or their residues.
Inadequate containment e.g. leakage.
Failure to store incompatible materials properly.
Lack of control of transfer operations - decanting, spraying, spillages.
Fire risks in construction and maintenance work
Site storage of flammable materials Improper waste disposal Demolition Oxy fuel cutting equipment Temporary electrical installations
Factors influencing arson risk
Type of business e.g. controversial activities
Location of premises e.g. inner-city areas, isolated areas, areas of high crime.
Whether the area is undergoing redevelopment.
VICES (flammable liquids storage)
Ventilation Ignition Containment Exchange Separation
DSEAR hierarchy of control
Elimination Control of risk Mitigation of consequences Safe handling, storage and transport General safety measures e.g. safe systems of work.
controlling sources of ignition
Using intrinsically safe equipment. Controlling the use of mobile phones. Maintenance and PAT testing. Designated smoking areas. Shielding to block radiant heat and sparks from hot work. Fire risk assessments.
Controlling sources of fuel
Segregating storage of incompatible substances.
Containment of leeks and spillages.
Precautions for filling and emptying containers.
Precaution for the transport of flammable materials e.g. loading and unloading, labelling, packaging and training.
Controlling sources of oxygen
- Closing doors and windows to limit natural ventilation.
- Shutting off forced ventilation systems and associated ducting.
- Safe use and storage of oxidising materials
Management of control measures
Implement safe systems of work.
Planned preventative maintenance programme.
Management of contractors.
Using permits to work.
Provision of information and training for employees.
General fire precautions during building maintenance and construction.
Prevention of arson.
INDG297 Safety in Gas welding and cutting.
Safety precautions when using oxy fuel equipment.
- Train staff in the safe use of equipment and fire precautions.
- Using proper equipment e.g. pressure regulators, flashback arrestors, non-return valves.
- Follow a permit to work system to include: moving workpiece to safe location.
Removing combustibles within 10 m of work.
Ventilating with vapours may accumulate.
Using guards/ covers to prevent hot particles.
Firewatch for one hour afterwards.
Fire extinguishers handy.
Work is authorised by competent person and time-limited.
Safe system of work
A formal procedure which results from systematic examination of a task in order to identify all the hazards. It defines safe methods to ensure that hazards are eliminated or risks minimised.
Management of contractors
Select with care.
Should be competent and able to conduct the work safely.
Have been properly inducted onto site.
Subject to performance monitoring.
Risks to maintaining fire protection systems during construction work
Detectors and sprinklers may be isolated.
Dismantling of walls may destroy integrity of compartment.
Fire escape routes may be blocked or rerouted.
Increase storage of combustible building materials.
Provisions of information and training
Employees need:
Information on hazards and controls.
Training in safe systems of work and procedures.
Actions to prevent arson attacks
- Perimeter fencing.
- CCTV.
- Intruder alarms.
- Floodlighting.
- Security guards.
- windows and doors locked outside normal working hours.
Remove entry rights for persons who have been dismissed.
Good standards of housekeeping.
Combustibles, flammables and rubbish located away from buildings but not near boundary.
Buffer zones between boundary and buildings.
Fire protected letter boxes.
Features of an external open-air storage location for flammable liquids
Secure, impervious, well ventilated, away from sources of ignition.
Sufficient separation from neighbouring buildings and boundaries:
- 2 metres up to 1000 litres.
- 4 metres up to 100000 litres.
7.5 metres over 100000 litres.
Design features of an outdoor building used to store flammable liquids in drums
Single storey building Constructed of non-combustible material. Lightweight roof. Adequate separation from other buildings. Good ventilation at high and low levels. Door sills to contain spillages. No potential ignition sources. Fire extinguishing equipment nearby. Appropriate signage.
Measures to reduce the risk from storage of flammable liquids inside workplace
Maximum 50litres in work area.
More than 50 litres should be kept outside work place away from buildings.
Use metal containers with non spill cap.
Keep containers in a fire-resisting cabinet.
Store empty containers away from full ones.
Prevent ignition sources.
Provide appropriate fire fighting equipment.
Employees instructed in emergency procedures.
Considerations for ANY flammable liquid storage facility.
Accessibility to firefighters. Provisions of escape routes. Fire fighting equipment (Incl sprinklers). Proper signage. Training for employees on hazards.
