Date of Issue: March 31, 2001
Hazard Summary
In the Summer of 1999, a metal box was blown-up when flammable gas that had escaped from oxygen/acetylene bottles was ignited.
An investigation by the Occupational Health and Safety Division of the Nova Scotia Department of Labour and Advanced Education determined:
- an explosive concentration of acetylene had accumulated in the bottom of the metal box
- cutting was conducted above the metal box, with sparks falling to the level below where the box was located
- the acetylene exploded when a spark fell to the bottom of the box.
Preventive Measures:
Storage
- Torches and oxygen/acetylene kits are not to be stored in metal gang boxes unless the boxes are designed and built for that purpose
- Follow manufacturer’s instructions/recommendations on the use of the gang box
- A safe work procedure for welding/cutting should include references to storage of oxygen/acetylene kits
Welding
- Safe work procedures must be developed by employers in consultation with the Joint Occupational Health and Safety Committees or Health and Safety Representatives
- All employees carrying out welding and cutting operations and those assisting, must be instructed in the safe work practices for welding and cutting.
Note:
Parts 5 and 10 of the Occupational Safety General Regulations set out requirements on how compressed gas cylinders are to be handled and how welding is to be carried out.
Work procedure requirements are called up through clause 28(2)(b) of the Occupational Health and Safety Act.
Information may also be found in Canadian Standards Association standard W117.2 - 01, "Safety in Welding, Cutting, and Allied Processes."