A few frequently asked questions about welding fume:
1) Which respirator do I need when welding stainless steel?
When welding stainless steel with MIG or MMAW, the welding fumes often contain particles of chromium and nickel, of which chromium is the more toxic. A powered air respirator with particle filter offers you excellent protection in this application. TIG welding does not usually emit much welding fume but creates large quantities of ozone gas. Plasma cutting and plasma welding give rise to high temperatures, which can emit damaging oxides of nitrogen
2) Do I really need respiratory protection when welding ordinary steel?
Although welding fumes from normal steel is not one of the more hazardous types, it is far from good for your health. Among other things, it contains particles of iron oxide, which can cause siderosis (chronic inflammation of the lungs). When welding with MIG/MAG or stick, there are heavy fume emissions, meaning that both a respirator and good ventilation in the workplace are necessary. When welding ordinary steel, a powered air respirator with particle filter is recommended.
3) What sort of respirator is needed when welding surface-treated material?
When welding surface-treated material, a number of hazardous pollutants can be released. When welding galvanised steel, zinc oxide particles are released. These can cause zinc ague, also known as fume fever. If you weld painted material you should be especially careful, as many paints can give off very hazardous air pollutants. When welding galvanised steel or material painted with lead primer, it is recommended that you use a powered air respirator with a particle filter and an odour filter to minimise unpleasant smells. If the material is painted with two component paint or insulated with polyurethane, you should always contact a Safety Engineer. There is a large risk that you will be exposed to isocyanates, which are very hazardous to inhale and difficult to detect. In these cases it is recommended that a supplied air respirator is used.
4) What respiratory protection do I need in restricted areas?
If you are welding in restricted or semi-ventilated areas — where there is a potential for build up of higher levels of contaminant and/or a reduction in oxygen levels — a supplied air respirator is suggested, regardless of welding method. With a supplied air respirator, providing breathable quality air, you can be confident of getting sufficient oxygen, as well as high levels of protection against gas and particulate contaminants. Powered or supplied air respirators are never to be used in atmospheres immediately dangerous to life or health (IDLH). Always ask a Safety Engineer if you are unsure!