Fire and explosion
Fires and explosions cause serious property damage in MVR and occasionally result in death or serious injury. Mostly, they involve the mishandling of petrol when draining fuel tanks and lines but incidents have also occurred during 'hot work' (any process which generates flames, sparks or heat) including repairs on diesel tanks (see further information below) or the inappropriate use of paints/thinners eg to light rubbish fires or clean paint booths. Make sure you use safe methods of work with flammable materials and high temperatures.
For information on hot work on wheels/tyres see Hot work on wheels page[48].
Fires/explosions during the burning of rubbish/waste materials
There have been several incidents at MVR premises in which employees have been seriously burned when waste thinners, petrol or other flammable liquid was being used to start fires. The materials being burned were mostly cardboard, paper, litter or other wastes. It is the flammable vapours which ignite which then engulf anybody nearby. Waste thinners or petrol must NOT be used to light fires or assist burning.
Safe use of petrol in garages
Fires and explosions caused by careless handling of petrol during vehicle repair and maintenance continue to occur throughout the country. Petrol fires are always serious and often result in fatal or major injuries, as well as major property damage. Always use a fuel retriever for draining tanks and lines, in particular following misfuelling diesel with petrol, and vice versa and don't mix the recovered fuel into the waste oil storage.
The safe use of petrol in garages publication. (PDF) [49]
Repair of diesel tanks
There have been a number of incidents at MVR premises in which employees suffered serious burns when the diesel tanks they were repairing exploded. The common feature in each case was the failure to have the tanks properly cleaned and gas freed before carrying out 'hot work' on them.
A careful assessment of the risks should be made before carrying out any process that generates flames, sparks or heat ('hot work') including welding, cutting, grinding and sawing. Other safer options should be considered including:
- using cold cutting or cold repair techniques; and
- replacing rather than repairing
Case studies
- An HGV diesel tank had split along the seams and it was decided to repair it by brazing. The tank was emptied using a hand-pump but not cleaned or gas-freed. The person carrying out the repair suffered the full force of the explosion and the fire-ball resulted in extensive burns.
- A welder received serious burn injuries when patch-welding a diesel tank from a bus. The tank was emptied using a fuel retriever and then drained. Although the outside of the tank was washed with a hot water pressure-washer, the inside was neither cleaned nor gas-freed.
- A motor mechanic removed the fuel gauge sender unit from the fuel tank and started to drain the petrol into a bucket. There was more petrol in the tank than he thought and it spilled onto the floor and caught fire. The mechanic sustained severe burns to hands, arms and legs and the workshop was completely destroyed.
- Mechanic was working in a vehicle inspection pit draining petrol from the fuel tank into a plastic bucket. The petrol vapours were ignited, possibly by a broken inspection lamp. The mechanic died from his injuries. There were several customers in the vicinity at the time who were also at risk.
- Self-employed car mechanic was siphoning petrol from one car and transferring it into the fuel tank of another when the vapours were ignited, possibly by a space heater at the rear of the workshop. There was an explosion then fire that completely destroyed the garage. The mechanic was seriously burned and died from his injuries.
- The proprietor of a garage suffered about 50% burns to his body when petrol vapours ignited. At the time, he was draining petrol from a fuel tank over a vehicle pit using a hose to transfer the petrol from the tank into 5 litre fuel cans.
Some dos and don'ts
- Use a proprietary fuel retriever/adaptor when draining petrol from tanks and lines
- Store containers of flammable liquids in a safe place
- Before carrying out any 'hot work' on drums or other containers that may contain vapours such as petrol, diesel, paints, solvents etc carefully consider the risks. Safer options include using cold cutting/repair techniques and replacing rather than repairing.
- Where 'hot work' on a tank or drum is necessary, reduce the risks by emptying, cleaning, gas-freeing or inerting.
- Don't drain petrol over or close to pit or drain
- Don't smoke, weld or carry out other 'hot work' while handling petrol or flammable paints/thinners
- Don't use petrol/thinners to burn rubbish or unwanted materials