Updated: Dec 2, 2020
As dangerous goods consultants we see a lot of common mistakes when storing liquefied petroleum gas (LPG) in exchange cages. In this article we look at the hazardous area requirements for LPG exchange cages.
This article is general information only. Want expert advice, specific to your needs: get in touch.
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LPG is stored in the gas bottles under pressure. If released from the container a highly flammable cloud will form. If the cloud encounters an ignition source, and is at the right ratio of oxygen to LPG an explosion can occur. The area where this flammable cloud can potentially exist is referred to as a Hazardous Area. These areas have a rating (zone) and dimensions (extents). The hazardous area formed depends on the source of the release and the ventilation in the area.
Hazardous Areas are also a legal risk in WA as they are covered under the Dangerous Goods Safety (Storage and handling of non-explosives) Regulations. Regulation 56 requires:
“An operator of a dangerous goods site must ensure that any ignition source in a hazardous area within the site is eliminated or, if this is not reasonably practicable, the risk arising from the ignition source is controlled.”
AS/NZS 1596 requires that the area 1.5m horizontally and 0.5m above the height of the cage is kept clear of ignition sources. Refer to the diagram below:
These extents assume your cage is outside with clear ventilation.
You need to keep the the area clear of all ignition sources. These could include:
Mechanical equipment - such as fans which can cause sparking
Open flames - such as pilot lights and smoking
Electrical equipment - such as lighting and power points
Hot surfaces - such as boilers, heated pipes, cooking implements
On the sites that Cadre have visited, the most common ignition sources have been:
Power outlets - whether something is plugged in or not
Night pay windows - with electronic equipment such as payment devices
Cigarette Bins - these can obstruct ventilation and also encourage people to smoke near the exchange cage
Where you can’t remove an ignition source the risk must be reduced in an alternative manner such as using electrical equipment which is rated for that Zone. If you have a setup which is slightly different to the standard exchange cage, a specific hazardous area classification may be required. Such an assessment needs to be performed by a suitably qualified person in accordance with the relevant part of AS/NZS 60079.10.
Need help with hazardous areas? Get in touch! Cadre has the experience and qualifications to let you know your exact requirements and help keep your site safe.
Did you have any of these issues on your site? Hopefully this article helped you understand the hazardous area requirements for your LPG cylinders. If you found that useful, check out some of the other common mistakes with LPG Exchange Cages:
If you have other dangerous goods storage onsite, we also have articles on some other dangerous goods storage types.
Although these are some common mistakes, remember there are a whole heap of other compliance and safety issues associated with LPG exchange cages. Make sure you check your DG risk assessment and get in touch if you have any questions!
This article was prepared as general guidance only and based on information current at time of publication. The use of this information is at the reader's own risk, Cadre Engineering accepts no liability for any outcomes of following this guidance. For expert advice, specific to your needs, please get in touch.