Aerosol cans are Class 2 Dangerous Goods and have been responsible for a number of workplace accidents in Australia as well as other parts of the world. Very often these little cans are not treated with the respect they deserve and many line supervisors and their staff seem unaware of their potential to ignite and explode. This blog demonstrates the different ways aerosols have contributed to workplace accidents and emphasises the importance of storing them correctly. Away from heat and ignition sources, and inside a dedicated aerosol cage.
Why aerosols need a dedicated storage solution
Aerosol cans are dangerous and have the potential to cause major workplace accidents for a number of reasons. These include:
1. Dispensed substances can be highly flammable
A worker was using an adhesive spray glue near a gas hot water system (despite being warned not to use the glue near an open flame). He accidentally dropped the can of adhesive and it landed near the burning pilot light. When he went to pick up the can he somehow depressed the spray button and ignited the glue. He suffered 2nd degree burns and was hospitalised.
Aerosol cans use propellants and solvents to dispense the active ingredient from the can (that’s the stuff you are using eg paint, WD40, glue) and maintain an even consistency. Hydrocarbons (propellants), methylal and dioxolane (aerosol solvents) are highly flammable and in many cases the active ingredient is flammable as well. Because of this aerosol cans are easily ignited when they are being used.
IMPORTANT: It is a requirement of AS/NZS 3833:2007 - The storage and handling of mixed classes of dangerous goods, in packages and intermediate bulk containers that aerosols must be kept at least 3 metres from heat and ignition sources.
2. Metal canisters can become dangerous projectiles
A worker was holding a can of spray paint as he walked through an industrial workshop. For some reason the aerosol can exploded and struck him in the chest. He died from internal injuries.
Aerosol cans are a self-contained dispensing system that store and discharge substances under pressure, the whole system is made up a number of different components that can become volatile if not handled or stored correctly. These include:
- Metal canister;
- Flammable propellant and solvents;
- The active ingredient itself (often flammable, corrosive and toxic);
- And the componentry of the metal valve (gaskets, metal spring, dip tube) valve cup and seat)
Workplace accidents where aerosol cans have unexpectedly launched into dangerous missiles have been documented in the USA and Australia. In these accidents workers received lacerations, broken bones, and facial injuries (eg, detached retinas and damaged tear ducts). In some of these accidents (like the one above) the workers have died.
IMPORTANT: Aerosol cans should be handled and stored according the manufacturer’s instructions used before the expiry date. Always check the Safety Data Sheet (SDS) that accompanies the spray cans for handling and storage essentials.
3. Cans explode when exposed to heat
Exposing aerosol canisters to heat is probably the most common cause of workplace accidents involving aerosols. Like in these three examples:
- Can of cooking oil left on the hot plate at a busy commercial kitchen explodes, burns two chefs, and blows out the front window of the cafe.
- Can of paint left in the sun is shaken for use and explodes in the hand of the worker.
- Can of adhesive spray left near a heat gun and explodes, an interior designer is burned and her workshop badly damaged.
Aerosol cans store substances under pressure, when the cans become hot the pressurised gas inside the can begins to expand. The pressurised can will eventually explode; the componentry scattered at high pressure as shrapnel; and the active ingredient, propellant and solvent likely to ignite. Imagine if this happened in your Dangerous Goods store.
IMPORTANT: It is a requirement of AS/NZS 3833:2007 - The storage and handling of mixed classes of dangerous goods, in packages and intermediate bulk containers that aerosol cans must be protected from the weather and direct sunlight.
What is a dedicated aerosol cage?
A dedicated aerosol cage is manufactured according to the strict guidelines of AS4332-2004 - The storage and handling of gases in cylinders. These cages fulfil a number of essential functions:
- Ventilation: Aerosol cages have perforated walls which provide natural ventilation. If a canister should leak the contents will dissipate naturally and won’t accumulate or cause pressure built up in the cabinet.
- Projectile Protection: Aerosol cages feature heavy duty steel construction and offer projectile projection if one (or all) of the cans happened to explode. The explosion would be contained within the cabinet.
- Weather Protection: Aerosol cages keep the cans undercover and protected from the weather and sunlight. Weather exposure can cause corrosion which may interfere with the valve and button componentry, while direct sunlight can deteriorate the can or cause it to overheat and explode.
- Isolation: Aerosol cages can be located and installed in safe areas at the job site away from flames, hot work, industrial heat, sunlight, static electricity, and other ignition sources.
- Security: Aerosol cages have sturdy bolt locks and can be padlocked so that unauthorised personnel cannot gain access to the aerosol cans. This is particularly important for aerosol spray paints.
- Shelving: The heavy duty shelving in aerosol cages are perfectly sized for aerosol cans. The cans are able to be stored singularly or in bulk (kept inside their original cartons). It is a requirements of Australian Safety Standards that cans are stored in a manner that reduces the risk of collapse of stacks or any damage to the aerosol containers.
Are you a WHS Manager of Supervisor responsible for managing the Dangerous Goods used and stored at your workplace? Why not download our free eBook Aerosol Safety and Storage, it’s an excellent resource for anyone wanting to know how to store aerosols and other compressed gases legally and safely. Download and read it today by clicking on the image below.