Explosion during the filling of scuba cylinders

Background

An employee recently sustained serious injuries after attempting to fill a scuba compressed air cylinder, which exploded. It is believed that the air cylinder had not been maintained and was not capable of holding the original fill pressure capacity, causing it to explode. The air cylinder shattered into a number of pieces, injuring the employee and placing others, in the area, at risk of serious injuries. There was also significant damage to the workplace.

Safety issues

Compressed air cylinders must undergo visual, hydrostatic and appropriate non-destructive testing every 12 months. Without regular inspections and testing there is a risk of serious or fatal injuries from a cylinder explosion.

For further information about inspection and testing see Australian Standard 2030.1-2009 Gas cylinders, General requirements.

Recommended ways to control risks

• Ensure the cylinder has undergone regular testing.
• Do not fill a cylinder without evidence of a valid inspection/test date within the last 12 months.
• Do not fill or use a cylinder if there is evidence of surface gouging, dents, broken fittings, corrosion or rust.
• If a cylinder leaks whilst filling, immediately cease filling, discharge the cylinder and evacuate the area.
• Do not fill a cylinder at a pressure greater than the working pressure stamped on the cylinder – if in doubt of the cylinder’s working pressure seek further advice from the manufacturer.
• Use proper cylinder filling equipment, follow procedures and refrain from fast filling.
• Do not tamper with the valve unit, safety valve fitting or rupture disc.
• Do not allow contaminants into your cylinder in the form of salt water or moisture.
• Do not leave a cylinder completely empty – leave a slight air pressure in the cylinder.
• Do not allow a cylinder to come in contact with fire or temperatures above 150C.
• Flexible connections (filling hoses) should be suitably restrained before filling, otherwise they may whip if the hose bursts or disconnects when pressurised.

Note: Do not use any cylinder which loses pressure or shows evidence of leakage, no matter how small. Leakage reduces calculated underwater time and may indicate imminent cylinder failure.

Safety checks

Before filling a cylinder, ensure:

• the cylinder has a valid test date
• the cylinder is free from damage, broken fittings or rust
• you have read and understood the filling instructions
• the appropriate personal protective equipment is being worn (eg hearing, eye and foot protection)

If you do not know the answer to any of the above, do not fill the cylinder, follow the recommended control risks and consult with your employer and or health and safety representative.

Legal duties

Under the Occupational Health and Safety Act 2004, employers must, so far as is reasonably practicable, provide and maintain a working environment that is safe and without risks to the health of employees and independent contractors. Where the risk cannot be eliminated, it must be reduced so far as is reasonably practicable.

Employers must also ensure, so far as is reasonably practicable, that persons other than employees are not exposed to health and safety risks arising from the employer’s undertaking.

Employers must provide employees with the necessary information, instruction, training or supervision to enable them to do their work in a way that is safe and without risks to health.

Employees must take reasonable care for their own health and safety at work, and the health and safety of others who may be affected by their acts or omissions at a workplace.

The Dangerous Goods (Storage and Handling) Regulations 2012 also sets out legal duties for occupiers of premises where dangerous goods are stored or handled. The Code of Practice for storage and handling of dangerous goods provides practical information on how to comply.

Please note the Dangerous Goods (Storage and Handling) Amendment (Notification) Regulations 2021 come into effect on 1 July 2021 (Amended Notification Regulations).

This information has not yet been updated to reflect the changes introduced by the Amended Notification Regulations. Complying with the guidance after 1 July 2021 may not necessarily mean compliance with a duty under the Amended Notification Regulations. Information on the Dangerous Goods Act 1985 and associated regulations can be found on:

Australian Standards

• AS 2299.1-2015 Occupational diving operations - Standard operational practice
• AS 2030.1-2009 Gas cylinders - General requirements
• AS 2337.1-2004 Gas cylinders test stations - General requirements, inspection and tests - Gas cylinders