Leaking gas cylinders can quickly create an asphyxiation risk to workers and personnel entering a (now) oxygen deficient atmosphere. This blog looks at how asphyxiation hazards are created by leaking gas cylinders, and how to minimise the likelihood of this happening at your workplace. Oxygen deficient environments are particularly deadly because they can impair the physical and cognitive functions of workers — often leading to fatal mistakes if operating plant and machinery or working at height.
The air around us that supports our life is made up of 21% oxygen, 78% nitrogen, and 1% mix of other gases. But oxygen content in the air can be depleted when other gases are released into the atmosphere, displacing the oxygen. Confined spaces are particularly vulnerable if there is no ventilation system in place to dissipate anomalies and maintain the correct percentages.
When gas under pressure leaks from a cylinder it can quickly fill a confined space and replace the oxygen. Once the atmosphere has less than 19.5% oxygen it is classified as an oxygen deficient environment — anything below 18% becoming a dangerous asphyxiation hazard. Workers or other personnel entering the area could quickly fall unconscious, stop breathing, and die.
The table below indicates the increasing risks to life (as well as cognitive impairment) when oxygen levels deplete:
Because many gases are both colourless and odourless, workers entering an oxygen deficient environment have very little warning the area is unsafe. At the same time their cognitive abilities become impaired without them realising. So it’s essential to make sure that handling and storage areas have adequate ventilation, and staff receive enough training and guidance to understand the potential dangers present on the job site.
IMPORTANT: Even inert gases like argon and helium (which are often considered safe because they are non-toxic, non-flammable and non-reactive) are potentially dangerous when leaked into a confined space.
Gas cylinders are heavy, bulky and awkward. Their long slim design (and their slippery surface) make them vulnerable to falling or being knocked over. Learning to handle and store gas cylinders correctly is the first step in preventing cylinders leaks.
Some essential steps include:
IMPORTANT: AS4332-2004 - The storage and handling of gases in cylinders requires that gas cylinders must ALWAYS be protected from being knocked over or falling.
Sometimes it only takes simple (but consistent) actions and maintenance to prevent gas cylinder leaks and asphyxiation hazards. The following examples are a good place to start:
IMPORTANT: Staff need to know what to do in the event of a gas leak. Hazards are compounded if using Class 2.1 Flammable Gases (you will require additional PPE and fire protection equipment) and Class 2.3 Toxic Gases (you may need PPE, first aid equipment, safety showers, eyewash stations, and breathing apparatus).
To learn more about your workplace responsibilities when handling and storing compressed gases in cylinders, download our free eBook Gas Cylinder Storage: Compliance and safety requirements. The eBook unpacks the requirements of AS4332-2004 - The storage and handling of gases in cylinders using real world examples to help you apply it to your own workplace or job site. Download it today by clicking on the image below: