Safety Alert – Hot work on small drums, barrels, tanks and containers
The HSA is issuing this safety alert following a recent serious accident. A person carrying out hot work on an ‘empty’ metal drum (200L) containing waste residue was fatally injured when the drum exploded.
This alert is aimed at persons who may cut up or repair drums, tanks or other containers as part of their work.
To avoid any risk, persons who require drums, barrels or any containers for storage of scrap or other material should not adapt old barrels / containers for use, but should purchase propriety containers from reputable suppliers.
Hot work is any process that generates flames, sparks or heat – it includes welding, cutting, grinding and sawing.
Drums or tanks which appear to be empty may contain sufficient residues of flammable material to cause an explosion when heated and turned into vapour.
Flammable liquids and vapours come in many forms such as diesel, petrol, fuel oil, paints, solvents, glues, lacquers and cleaning agents. If a welding torch, gas cutting torch, electric arc, powered cutter or any heat source is applied to a drum or tank (either sealed or open) containing flammable material (solid, liquid, vapour) the drum or tank can explode violently.
Never apply heat to any drum, tank or container before ascertaining its contents and assessing the risk of fire and explosion. Even a tea spoon of flammable liquid in a drum can be enough to cause an explosion.
Hot work should not be carried out unless it is authorised and supervised by an experienced and competent supervisor, who has knowledge of the work, the risks involved and precautions to be taken.
Before carrying out any hot work, Employers must carry out an assessment of the risks. Other safer options should be considered such as:
- Replacing, rather than repairing and
- Using cold cutting or cold repair techniques.
If hot work is required the risks may be avoided by using a specialist company or reduced by using methods such as gas-freeing, cleaning or inerting before hot working.
Drums, barrels, tanks or other containers should not be repaired or cut up unless absolutely necessary and then after the operator has received adequate training in the risks involved and precautions to be taken.
General Advice on hot work
If there is no alternative to hot working, the tank, the drum or container should be emptied and washed thoroughly by steam cleaning or other means. To reduce the risk, the air in the tank can be replaced, e.g. by using water. Ensure the tank is not sealed and can be vented to release steam. The services of a specialist should also be used if filling with inert gas.
Note: Cold work can also produce heat and is not completely without risk.
Waste water should be disposed of in line with environmental requirements.
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