Workplace Safety, Health and Environment (WHS)
Why WHS comes first
In welding, the hazard is created by the work itself: heat, light, fume, electricity and gas. A candidate must know the hierarchy of control (eliminate, substitute, engineer, administrate, PPE last) and be able to name controls for each hazard class rather than recite a single favourite answer.
Core concepts
- Fume and ventilation: welding fume is a respiratory hazard; local exhaust ventilation at the arc, general dilution ventilation, and respiratory protection where extraction is inadequate. Confined spaces need gas testing and a standby person, never ventilation alone.
- Radiation and burns: arc eye (photokeratitis) from UV; shade numbers rise with current and process; screens and flash glasses protect bystanders; PPE includes leathers, gloves, spats, and flame-resistant clothing.
- Electricity: welding circuits are often open-circuit 50-90 V. Wet conditions, damaged leads, and secondary-earth problems cause shocks. Isolate before changing electrodes or leads.
- Fire and explosion: hot work permits, a fire watch, 10 m clearance of combustibles (or shielding), and gas cylinders stored upright, secured, with flashback arrestors.
- Hazardous substances and environment: degreasers, solvents, and coatings can decompose into toxic products; capture, substitute, and dispose of waste and spent consumables correctly.
Traps
Questions often present a control that is last in the hierarchy (PPE) as the correct answer, or mix up extraction with respirators. Another trap is confusing a hot work permit with a confined-space entry permit; both may be needed. Watch for 'always' and 'never' statements about ventilation in tanks.
Rule of thumb
If you can smell or see fume, extraction is not working. Treat any enclosed or poorly ventilated space as a confined space until tested and permitted.