Occupational Safety, Health and Environment in Welding
This domain tests hazard recognition and control in welding: arc radiation, fume, fire, electric shock, gas cylinders and confined spaces. Questions often ask for the best control, not the quickest one.
Core rules
- Wear a welding helmet with the correct filter shade, leather gloves, flame-resistant sleeves, safety boots and eye protection for chipping. For SMAW around 100–200 A, shade 10–11 is typical.
- Keep fume exposure low with local exhaust ventilation at the arc. In confined spaces, test the atmosphere, ventilate, use a trained attendant and a rescue plan.
- Electrical safety: dry insulated gloves, undamaged electrode holder and cables, tight earth clamp near the work, and no welding in wet conditions without isolation.
- Hot work: permit, remove combustibles within about 10 m, use fire blankets, and keep a fire watch for at least 60 minutes after finishing.
- Gas cylinders: upright, secured, valve caps fitted when moved, flashback arrestors on acetylene and oxygen lines, and no oil or grease on oxygen fittings.
Worked example
Hot work ends at 15:30. The fire watch must continue for 60 minutes, so the area is checked until 16:30. If smouldering is found, the watch continues and the fire service or site emergency team is called. Reasoning: slag and sparks can start a slow fire after welding stops.
Traps that cost marks
- Treating arc eye as minor; adjacent workers also need screens and warning.
- Using oxygen to blow dust from clothing; oxygen makes fabric burn fiercely.
- Entering a confined space without gas testing because it “looks clean”.
- Leaving a hot workpiece unmarked and unattended.