Gas bottles and cylinders are pressure vessels that are used to store gases at extremely high pressures. The gases stored within these cylinders are often dangerous. The two main types of dangerous gases that are stored within gas cylinders include:
- Class 2.1 - Flammable Gas
- Class 2.3 - Toxic Gas
Other classes of dangerous goods that are often stored within gas cylinders include class 2.2 - non-flammable, non-toxic gas.
Gas bottles and cylinders pose an extreme risk to people and property even when the gases within the gas cylinder are non-hazardous. This risk is due to the extreme pressure of the gas within the cylinder. If a gas cylinder tipped over and the valve block sheared off, the contents within the gas cylinder would rapidly disperse. The rapid dispersion of these gases would cause the gas cylinder to become a flying projectile, potentially causing property damage, injury or death.
The storage and handling of gas cylinders is regulated in Australia to help prevent the risks that they pose upon people and property in the workplace. Each State and Territory of Australia have their own laws to regulate the storage and handling of gases in cylinders. The requirements of these regulations sightly differ from state to state.
If your organisation operates across a number of States and Territories, it can be hard to comply with the different regulations that apply to each State and Territory. This problem can be overcome by following the requirements outlined in the Australian Standards. The Australian Standards are national standards that are accepted as an important part of meeting regulatory compliance. The Australian Standard that outlines the requirements for the storage and handling of gases in cylinders is AS 4332-2004. An overview of the storage and handling requirements according to this standard are outlined below.
Gas cylinder store construction requirements
- Gas cylinder stores must be constructed from non-combustible material
- The base of the gas cylinder store must be level. If drainage is required the floor must be sloped in a way that doesn’t compromise cylinder stability.
- Any space between the base of the gas cylinder store and the ground must be filled with a solid non-combustible material, or have at least 2 ends completely open to the air.
- Any gas cylinder store that is attached to or located within a building must be separated from the rest of the building by one or more walls. Each of the walls must have a fire-resistance level (FRL) of 240/240/240.
- The floor above any gas cylinder store in a multistory building must be constructed of a material having a fire-resistance rating of 180/180/180.
- The walls and roof of gas cylinder stores must be of a non-combustible material. Where practical the supporting structure must also be of non-combustible material.
- Bollards and crash barriers must be installed where there is a risk of cylinders being damaged by vehicles in the surrounding area.
- Ignition sources must be excluded from any gas cylinder store containing flammable gases.
- The doors of gas cylinder stores must open outwards or be a ventilated roller door that can be opened from inside the store.
- Any electrical equipment installed in gas cylinder stores must comply with AS/NZS 3000 and all electrical fittings must be installed in a way that prevents them from being damaged by impact from cylinders.
- Gas cylinder stores must also have gas cylinder restraint bars and chains to prevent the gas bottles from falling over.
- Gas cylinder stores can be located indoors or outdoors, however the indoor storage of compressed gases must be avoided at all times.
Gas cylinder store lighting requirements
In areas where gas bottle cages are located there must be sufficient lighting to enable personnel to read the markings on gas cylinders, signs and gas cylinder instruments such as regulators. Also to allow for safe escape in the event of an emergency, all internal roads that lead to areas, rooms or stores where gas cylinders are kept must be sufficiently illuminated.
To ensure that any gases that may leak from gas cylinders don’t build up inside the store, all gas cylinder stores must be sufficiently ventilated. A ventilation system must be capable of:
- Diluting any vapours or gases within the store to levels below the workplace exposure limits.
- Providing sufficient fresh air from outside to reduce the risk of asphyxiation.
- Sufficiently ventilating the atmosphere within the store at high and low levels relative to the floor.
These ventilation requirements can be achieved with either a natural or mechanical ventilation system. A mechanical ventilation system for flammable gas cylinder stores must be intrinsically safe to prevent the risk of fires. Intrinsically safe ventilation systems can be impractical in the outdoor environments and therefore natural ventilation systems are often the preferred option. A natural ventilation system can be achieved by having two opposing walls open to the outside atmosphere. These walls can be covered with a wall of wire mesh or louvers.
Dangerous goods signage
To ensure that everyone in the workplace is aware of the specific risks associated with dangerous gases stored in the workplace, it is very important to have the correct dangerous goods signage on all gas cylinder stores. There are three different classes of dangerous gases and each class requires different signage. The signage requirements for each class are outlined below.
Class 2.1 - Flammable Gas
Class 2.2 - Non Flammable Non Toxic Gas
Class 2.3 - Toxic Gas
All gas cylinder stores must also have a sign that states “No Smoking No Ignition Sources Within 3m”. An example of this sign is shown below:
No Smoking No Ignition Sources Within 3m
As there are many risks associated with the storage and handling of gases in cylinders, it is very important to store gas cylinders in a safe and compliant manner. Safe gas cylinder storage can be achieved by adhering to the requirements outlined in the Australian Standard AS4332-2004. If you would like more information on how to safely store flammable gases and other flammable material, download our FREE eBook by clicking on the image below.