We carry out DSEAR assessments across the UK and on many of the sites we visit they have compressed gas cylinders; some of which may contain hazardous substances such as Propane, Acetylene and Hydrogen etc. Although these can be in common use it seems that quite often, the risks of using and storage of these gases is not widely understood.

In many assessments we have to make recommendations to the businesses we are working with, so that they can improve the controls surrounding hazardous gases. This is important because a failure to properly control safe use and storage could lead to a major event for the business (including the implications of a 200 metre exclusion zone in the event of a fire – which for Acetylene can extend to 24 hours). It is important that robust controls are applied and these should include:

• PTW authorisation;
• Appropriate safe storage;
• Training for those using;
• Ensuring suitable flashback arresters are fitted;
• Cylinders should be part of a planned preventative maintenance scheme;
• Inspection by competent persons and the changing of regulators as required.

Fires or explosion hazards arise when flammable vapour or liquid is released into areas where there may be an ignition source – for example, leaks from gas hoses where someone is using unprotected electrical equipment. Both Propane and Acetylene require low concentrations to form an explosive mixture and therefore need to be well controlled; it is usual practice that where gases are used outside of a dedicated area (e.g. welding bay) that a PTW system is used as part of the risk control management.

A defining principle for DSEAR is to reduce the quantity of dangerous substances held on-site to a minimum. Regulation 6 identifies that where it is reasonably practicable, an employer should reduce the risk by substituting the dangerous substance with one that is not dangerous, or less dangerous.  We often suggest a review of where Acetylene is in use to determine if other gases could be used or if it could be brought to site only when it is needed to be used.

Ideally, all gases should be stored externally in suitable cages, keeping hazardous gases separated (including full and empty cylinders). Where dangerous substances that are gases are stored inside a work area they should be in a separate room (kept locked and signed) and should be located in a safe position or constructed of a fire-resisting material.

For more information on controlling hazardous gases or any other DSEAR risks then please contact us.