Fires and explosions caused by hot work have claimed the lives of many workers over the years. The risks have been known for many years but accidents still happen and people are still getting killed.
If you going to weld or flame cut drums and tanks make sure you’re not going to cause an explosion or fire. Free HSE guidance INDG 314 “Hot work on Drums and Tanks” gives a simple description of the safe way to do this work.
HSE information sheet CS15 Inerting and gas freeing of tanks containing flammable residues contains detailed descriptions of this process. You should use similar procedures for work on pipes or other enclosed areas where flammable substances and residues may be found.
Explosions are rare but it is possible. Acetylene is very explosive, even in small amounts. A leak of acetylene gas in to the back of a van is a very serous situation and should be prevented. If have to carry any gas cylinder inside a vehicle you should always close the main cylinder valve. It’s the best way to prevent leaks. British Compressed Gases Association publish an example risk assessment (ref TIS15) and other relevant guidance on their website. Most Technical Information Sheets (TIS) and Leaflets can be downloaded freely.
Hot metal parts, sparks and drips of molten metal can easily start a fire. You should clear away wood, fabric, cardboard and other flammable material before starting the job. Remember that the heat, sparks and drips of metal and slag can travel a considerable distance and can start fires in adjacent rooms.
You may need a person to act as a fire watcher. They should remain on watch for at least 30 minutes after the hot work finishes.
Welding and cutting inside ships and other enclosed spaces is particularly dangerous as smoke from fires cannot escape and will quickly overcome people working nearby.