This guiding principle is intended to outline the hazards associated with hot work and highlight measures to mitigate the risks of injury, fire and/or explosions.
- Hazards involved in hot work
- General hot work requirements (designated/prohibited areas)
- Pre-user checks (hot work equipment)
- Controlling Hazards During Hot Work
Hot work includes any process that generates a source of ignition, such as naked flames, heat or sparks arising from working methods (e.g. welding, grinding, cutting). Hot work is a major cause of injuries, fires and explosions in the work place. The main hazards involved include:
Burns: Burns can be caused by the heat radiation from hot work either by direct contact with the flame/ hot surface or sparks generated during work.
Eye Damage: If unprotected, the eyes can be damage by the radiation generated during welding or sparks during grinding or cutting.
Fire caused by heat, sparks, molten metal or direct contact with the flame: The flame from a torch can quickly cause combustible material such as wood, paper and plastics to catch fire, if not properly controlled. In addition, most hot work tends to produce sparks and hot splatter which can also ignite these materials if they are left lying around the workstation (e.g. grinding).
Fire or explosion caused by gas leaks: Fuel gasses such as acetylene are highly flammable and form explosive mixtures with air and oxygen. Even small gas leaks can result in a flash fire or explosion if allowed to accumulate in the work space. Gas leaks often result from poorly maintained or damaged equipment, poor connections or not closing valves properly after work. It is important that precautions are taken to prevent leaks during hot work.
Flashbacks: A flashback is usually caused by a reverse flow of oxygen into the gas hose, or fuel into the oxygen hose, which produces an explosive mixture. As a result, the flame may burn back through the torch into the hose and potentially reach the regulator/cylinder. Flashbacks can result in damage to cylinders/equipment and can even cause cylinders to explode, subjecting workers to severe injury or worse.
Fumes created during welding: The fume from welding and flame cutting metals is harmful and can cause several short/long-term illnesses if workers are exposed to it. Dirt, grease and other contamination (e.g. paints) increases the amount of fume generated and can introduce toxic substances into the air. Fume extraction and/or filtering respirators (respiratory protective equipment or RPE) are necessary to reduce the risk of ill health.
- Work must be authorised by a valid Hot Work Permit.
- Compulsory eyes, heat and respiratory PPE must be properly worn.
- All individuals performing hot work must be informed of the associated risks, including the effect on the surrounding areas.
- Ensure sufficient ventilation and fire prevention measures are present.
- Continuous monitoring is required for hot work being conducted in hazardous areas.