Three weeks ago a worker in North Queensland was killed while making a counter weight for a tractor by welding empty fuel drums to a steel frame.
The man sustained full thickness burns to more than 95 per cent of his body. He was transported to Cairns Hospital where he passed away from his injuries.
The tragedy is a sobering reminder of the dangers involved in cutting or welding drums, a common practice on farms to create storage, feed or water troughs, or as it gets colder, ready-made fire pits.
Welding on the rim of a truck tyre while it is inflated is another associated high risk activity.
“Every year we have a number of fatalities and/or severe injury from these type of activities,” said Farmsafe Queensland’s Jamie Cupples.
Each year in Queensland alone there are approximately 27 workers’ compensation claims involving an explosion.
Of these claims, almost 40 per cent result in a serious injury with five days or more off work.
On average, there is one fatality every year.
Since 2012, Workplace Health and Safety Queensland (WHSQ) says it has been notified of 11 events pertaining to workers or bystanders welding a container when it exploded, two of these involved a fatality.
In the same period, 14 notices were issued by Workplace Health and Safety Queensland – 13 improvement notices and one prohibition notice pertaining to workers or bystanders welding a container when it exploded (or the risk of same).
Preventing a similar incident
Welding generates heat, flames and sparks – all of which are sources of ignition.
When combined with fuel and oxygen, sources of ignition present a significant risk of fire and explosion.
While the greatest risks are with common flammable liquids like petrol, avgas, and ethanol, combustible liquids such as diesel fuel and oils can behave like flammable liquids when they are heated.
When heated, these liquids may generate vapours that, when confined, can also cause an explosion when ignited. You must manage health and safety risks associated with an ignition source in an atmosphere that has a concentration of flammable gas, vapour, mist or fumes that exceed 5 per cent of its lower flammability limit (hazardous atmosphere).
This includes identifying all sources of ignition, such as welding, hot-cutting, and grinding which generate heat, flames and sparks.
Reuse of fuel containers should be avoided and be properly disposed of.
Control measures to manage fire and explosion risks include:
- Isolate fuel sources from ignition sources so they cannot interact.
- Remove all traces of flammable or combustible materials from containers such as drums, vessels and tanks prior to welding or similar hot-work activity. This may require cleaning, noting that:
- unless containers have been cleaned out to be free of flammable and combustible substances, vapours can remain in containers for many years, and
- rinsing drums may not be enough to remove vapours from within a container.
- Purging or filling with an inert substance such as nitrogen gas or water, noting that use of inert gases may introduce other risks.
- Ensure all containers are properly labelled.
- Use fire resistant barriers to prevent welding sparks reaching flammable and combustible materials.
- Check work areas are well ventilated to prevent accumulation of flammable vapours in the work area.
- Check work area is free from rubbish, paper or dust that could be potential fuel sources or produce dust explosions.
- Do not store flammable and combustible materials near welding area.
- Keep and maintain fire-fighting equipment near welding area.
- Ensure the appropriate personal protective equipment is worn for the activity undertaken.
Prosecutions and compliance
In 2015, a worker was fined $2500 and given a training order after welding and steel grinding close to pressurised spray paint cans which resulted in an explosion.
The defendant, and two other workers who came to assist, sustained burns. The defendant was instructed in safe work procedure and had signed his employer’s register.
The safe work procedure identified hazards and risks associated with hot work and nominated that flammable and combustible items were not to be in the vicinity of hot work activities. The worker failed to follow the procedure.
In 2013, a company was fined $125,000 and given a two year court-ordered undertaking and a training order following the death of a worker who was welding a sealed oil tank.
The worker, who was not a qualified boilermaker, was welding a funnel onto the tank which had not been purged of oil or waste fuel products, causing a catastrophic rupture.
Sources: Farmsafe Queensland, Workplace Health and Safety Queensland