Welding safety
Personal protection, fume extraction, hot work, electrical safety, first aid.
Four hazards, and each has a standard behind it: eyes and skin from radiation and spatter, lungs from fume, the building from fire, and the welder from electric shock.
Two of them are underestimated in a specific way. Fume was reclassified as a Group 1 carcinogen in 2017 — all welding fume, not only the stainless fraction — and the control that works is extraction at the arc, not an open door. Electric shock is dismissed because welding voltage is low, but the voltage that matters is the open-circuit voltage before the arc strikes, and the danger threshold falls sharply on wet skin.
The third, fire, is mostly about time: most hot work fires begin an hour or more after everyone has left.
- Personal protective equipment Helmet, gloves, jacket, boots and respirator: the standards they must meet, and the mistakes that cause most burns and eye flash.
- Welding fume and ventilation What welding fume contains, why stainless and galvanised steel are worse, the exposure limits and how to extract at the arc.
- Hot work and fire safety Why sparks start fires hours later, what a hot work permit covers, and how to leave a site with nothing left smouldering.
- Electrical safety in welding Why open-circuit voltage matters, where the return clamp belongs, and what makes damp and confined spaces genuinely dangerous.
Frequently asked questions
Is welding fume really carcinogenic?
Yes — the IARC reclassified all welding fume as a Group 1 carcinogen in 2017, not only the stainless-steel fraction. That is why extraction requirements tightened across Europe afterwards, and why an open door does not count as a control.
Welding voltage is low. Is electric shock a real risk?
Yes. The figure that matters is the open-circuit voltage before the arc strikes — 50 to 90 V, up to 113 V on some AC machines — and the danger threshold is around 50 V. Wet skin drops the body's resistance by an order of magnitude.
How long does a fire watch have to stay?
At least an hour after the work finishes, and two under some regimes. Most hot work fires start after everyone has left, from a spark that smouldered in dust or insulation.