As compressed gas creates a range of hazards in a workplace, an integral part of managing the risks is to make sure that gas cylinders are stored safely and correctly. This post highlights the key storage requirements of the Australian Standard AS 4332:2004 - The storage and handling of gases in cylinders and offers practical suggestions to increase safety in your gas cylinder stores.
More specifically we’ll be discussing:
IMPORTANT: Cylinder stores must also have first aid stations appropriate for the gases being used — toxic and corrosive gases will also require eye wash stations and safety showers.
Wherever possible, compressed gases in cylinders should NOT be stored indoors. Cylinder stores need good ventilation that keeps oxygen at safe levels and escaped gases within explosion limits. Therefore, when considering the location of gas cylinder stores, outdoors is always the best place.
Outdoor locations minimise the risks associated with hazardous gas leaks in the workplace.
Any leaked gas becomes an immediate hazard — especially when the gas is toxic, corrosive or flammable. When stored outdoors, leaked gases will often disperse safely into the atmosphere. However, if gases are stored indoors, there is the risk that gases will begin to accumulate – especially if the gas is denser than air.
If workers enter an indoor area contaminated by a gas leak, it could result in:
When selecting a suitable space at your worksite for cylinders stores, you should make sure the area is not exposed to plant or production operations that generate heat or other ignition sources.
Additionally, the area requires a 3 metre clearance from any combustible materials, vegetation and refuse.
If you’re storing flammable gas, make sure the storage area is designated NO SMOKING.
Finally choose a location away from building windows, doors, air vents and ducting; the Australian Standard requires a minimum clearance of 1 metre.
For optimum storage safety, all gas cylinders must be stored in a compliant gas bottle cage that has been manufactured in full conformance to the Australian Standard AS 4332.
IMPORTANT: Gas cylinders should not be stored indoors unless the building has been specifically designed for this type of storage and has appropriate fire rated walls and ventilation. If outdoor storage is not possible, a mechanical ventilation system using exhaust fans and ducting may need to be installed. You may also require air quality monitoring controls and alarms.
Most gas cylinders are heavy and feature a long, slim design. Due to their weight and design, there is high possibility of cylinders falling or being knocked over in the workplace.
Therefore, the Australian Standard states that cylinders must be securely restrained in a way that cannot cause damage to valves or regulators.
The best way of achieving this is to install a sturdy gas bottle cage, made from heavy duty materials. The cage will have a secure racking system and safety straps (to prevent damage from forklifts or other traffic).
Apart from adequately restraining cylinders, a gas bottle cage can be locked to secure the cylinders against unauthorised access. This is another essential requirement of the Standard.
Unrestrained gas cylinders can become unstable and cause serious accidents in the workplace.
Keep in mind that most accidents or injuries involving cylinders happen when they are being moved.
REMEMBER: As cylinders are often big, bulky and awkward to move, it’s quite easy to knock them over or have them slip while you are manoeuvring them. Make sure your staff are trained correctly, use gas cylinder trolleys, and always wearing PPE appropriate for the gas inside when handling the cylinder.
Cylinders should always be grouped according to their dangerous goods class. They must also be correctly segregated from incompatible gases and hazardous chemicals.
The Standard requires (as a minimum) that the following gases are separated by at least 3 metres due to incompatibility and the potential for hazards:
The same segregation rules also apply to empty cylinders.
Separate empty gas cylinders from full cylinders and label and store them at another location. Your empty cylinder store should be treated in the same way as full cylinders: with bottles restrained, stored upright with the valves closed and fully segregated.
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Like all hazardous chemicals and dangerous goods, gas cylinders require clear signage that complies with the current WHS Regulation in your state or territory. Additionally, you should refer to the Code of Practice for Labelling of Workplace Hazardous Chemicals released by SafeWork Australia.
In brief, cylinder stores require mandatory placards outside the storage area.
These placards must be:
The placard signs need to be visible at the premises and at each building or other facility where the cylinders are stored or handled.
The placards used will depend on the hazard class of the gas and will be a combination of pictograms (graphical representation of the hazard class), signal words (DANGER, WARNING), hazard statements (Highly Flammable) and precautionary statements (store locked up in a well-ventilated place).
Below are the signage requirements for each class of gas:
Always check with your supplier and the safety data sheet for accurate specifications on the dangerous goods class and hazards associated with your gas cylinder. You’ll also need safety data sheets for each gas kept in a Manifest Cabinet close to the gas cylinder storage area.
As we’ve outlined in our post, storing cylinders correctly is the key to managing the risks associated with compressed gases. If you’d like to learn more about the hazards of gas cylinders and how to control them, why not download our free eBook? Gas Cylinder Storage: Compliance and Safety Requirements unpacks the requirements of AS 4332:2004 into clear, actionable advice for business owners, WHS and Compliance Managers.