Health, safety and environment
Health, safety and environment tests hazard recognition and the hierarchy of control for welding operations - in the workshop and on site, including confined spaces and hot work.
Principal hazards
- Fume: manganese and hexavalent chromium from stainless; zinc oxide from galvanised steel causes metal fume fever.
- Gases: CO2 and argon displace oxygen in pits and tanks; ozone and nitrogen oxides form in TIG/MIG arcs.
- Radiation: UV causes arc eye and skin burns; IR heats the skin.
- Electricity: open-circuit voltage, wet conditions and damaged leads.
- Fire and explosion: sparks travel; cylinders and fuel must be separated.
- Noise, heat, hot surfaces and manual handling.
Controls, in order
Eliminate or substitute (remove galvanising, use a lower-fume process), engineer (LEV at the arc, torch extraction, general ventilation), administrate (hot work permit, gas testing, exclusion zones), then PPE: helmet with correct shade, typically 10–13 depending on process and current; flame-retardant clothing; leather gloves; RPE P3 where extraction is inadequate.
Confined spaces
Gas test before entry and continuously, attendant at the entry, rescue plan, forced ventilation - never oxygen. Cylinders and hoses stay outside.
Worked example
Welding galvanised steel inside a tank: strip zinc 50 mm each side of the weld, use LEV and P3 RPE, gas-test for oxygen and flammables, keep an attendant. Zinc fume causes metal fume fever, but the confined space makes oxygen deficiency and fume accumulation the fatal risks, so engineering controls and the entry procedure come before PPE.
Traps
Treating PPE as the first control; ventilating with oxygen; assuming a welding helmet protects against grinding; ignoring fume from self-shielded FCAW.