Many workplace accidents involving flammable liquids could have been prevented if the staff had a greater understanding of the flashpoint, plus the fire and explosion limits of the substances they were handling before the accident. Accidents involving flammables very often involve catastrophic explosions which cause horrendous injuries to workers. This blog presents a number of real workplace accidents involving flammable liquids — where it seems the worker did not fully understand the risks and hazards to their safety. In many cases the workers died from the terrible burns they sustained after the subsequent fires and explosions.
1. Using petrol or gasoline to accelerate a fire
A employee at a job site that manufactures wooden windows and doors went to light a wood fire in a furnace. Starting the fire with wood and kindling he also placed petrol in the firebox to accelerate the fire. The vapours ignited instantly and flashed over the employee, who caught on fire. He died from second and third degree burns.
Many workers don’t understand that it is actually the vapours that ignite and burn rather than the flammable liquid itself. When you throw petrol, solvents or other accelerants onto a fire, the flames will follow the vapours back to the source — usually a worker’s hand holding a bottle or container of fuel. Even if the flammable liquid giving off the vapour is located a long distance from an ignition source (even 100 metres away), flashback and fire can still occur.
If you have areas at your worksite where staff are required to light furnaces or burn materials, ensure your staff have sufficient materials to ignite the fire safely and are trained not to use accelerants. Make sure that staff understand the chemical properties of the flammable liquids they are handling and the vapours they emit.
2. Bringing an ignition source into an area containing flammable liquids
A worker was transferring a flammable liquid called RC-250 (a type of asphalt) from a tank to his truck, but when he finished he realised the transfer line had become stuck because of the extremely cold weather. He attempted to unfreeze the line with a propane blow torch. The fuel instantly ignited causing an explosion. Sadly the worker was killed.
AS 1940:2017 - The storage and handling of flammable and combustible liquids requires that ignition sources must not be brought into areas where flammable liquids are stored, handled or dispensed — this include bulk storage tanks, packaging areas, minor stores and fill points.
In this terrible accident it is clear the worker did not understand the hazards of the RC-250 including it’s reactivity, flashpoint or explosion limits. All staff handling flammable liquids must be given thorough safety training so that they are:
- Familiar with the Safety Data Sheets (SDSs) of the flammable liquids they use and have a full understanding of their chemical properties — eg, generic SDSs for RC-250 state the chemical should not be exposed to heat, flames and oxidisers.
- Conversant with ignition sources (naked flames, welding arcs, mechanical sparks, electrical discharge from static electricity, machine heat) that could ignite the flammable liquids.
- Aware of their personal responsibilities under WHS legislation and Standards.
- Able to prepare their work areas safely and follow correct procedures (eg, earthing and bunding, liquid dispensing, spill response, waste removal).
IMPORTANT: There must be no uncontrolled sources of ignition in any space in which a flammable mixture of vapour and air could be present.
3. Using incorrect decanting methods
A new employee working alone in a warehouse was transferring the solvent acetone from an elevated Intermediate Bulk Container (IBC) to another container located on the ground. He used the forklift to elevate the IBC but the transfer hose broke and acetone liquid began to spill out on the floor. Unable to reach the main valve he tried using the forklift again to manoeuvre the IBC, at the same time acetone vapours reached the hot surface of the forklift engine and ignited. The worker received 3rd degree burns to more than 60% of his body and died one month later from his injuries.
Care should be taken when decanting or transferring flammable liquids and staff need thorough training. New workers especially require additional supervision and should not be left alone to handle Dangerous Goods. Using a flammable liquids dispensing station designed in accordance with AS1940 is an excellent way of reducing the risk of spills and dispersion of flammable vapours.
A dispensing station allows you to store and dispense your flammable liquids from a single unit. Well designed dispensing stations are fully enclosed and are fitted with a spill containment sump, natural ventilation system, as well as hose reels, dispensers and pumps.
4. Not bunding dispensing equipment
A worker was dispensing fuel from large drums into small bottles. He was using drums, a pump, polyurethane hose, a liquid filling machine, and the small bottles. Most of the equipment was grounded however the polyurethane hose had not been correctly bunded. Static electricity ignited a flash fire and the employee was hospitalised after suffering first and second degree burns.
When transferring flammable liquids into another container or tank, all the dispensing equipment (piping, tanks, valves, containers etc) must be bunded continuously. Fuel passing through a hose and between containers creates static electricity and that electricity most commonly discharges as a nozzle is being removed from a tank that is being filled.
The process of bunding ensures that an electrically conductive pathway between a dispensing container, and a receiving container is always grounded. It is essential that your dispensing stations have bunding systems in place and staff are given thorough training on the importance of bunding and the risks to their own health and safety if they dispense fuel without grounding the equipment. Staff also require adequate supervision to ensure they are correctly following safety procedures.
5. Not maintaining vapours within safe exposure levels
An employee was using a flammable solvent to remove linoleum adhesive from the floor of a laundry room. The laundry was empty except for some cabinets, a hot water system and solar storage tank. Working with the doors closed and only a window open, the room did not receive adequate ventilation as the flammable vapours were released. The heating elements from the hot water system ignited the solvent vapours causing an explosion and flash fire. The employee died from injuries he sustained in the fire including 2nd and 3rd degree burns to more than 85% of his body.
When working with flammable liquids and other chemicals it is essential to maintain exposure levels below the exposure standards published by Safe Work Australia. This includes the vapours released while fuel or solvents are being used or transferred.
Staff require sufficient training so they know how to adequately ventilate their work area especially when working in different areas of the worksite, or on the premises of customers and contractors. If no mechanical ventilation system is in place they should understand how to increase the amount of fresh air supplied to their work areas by opening windows and doors. At the same time staff need to remove potential ignition sources in the area (in this case turning off the hot water system).
Minimising the harm associated with the flammable liquids at your worksite requires a full risk assessment. Why not download our free eBook How to Reduce the Risk of Flammable Liquids in the Workplace where we introduce our four-step risk assessment methodology, and explain how to apply it to the flammable liquid hazards at your own worksite. Download and read it today.