The exposure of welders in Dutch industries to total particulate, chromium, nickel and copper fume during the welding of unalloyed, stainless and high alloyed steels has been investigated. The exposure to the gases NO 2 , NO and ozone is also discussed. The results are presented in tables and graphs. The correlation between the arc-time factor and the welding fume concentration in the breathing zone appeared to be bad. MMA-welding fumes of stainless steel contain mainly soluble hexavalent chromium. During MIG and TIG welding the fumes contain chromium which was insoluble in water and not hexavalent. The nickel was insoluble in water in all three processes. In comparison with the Dutch occupational health standards, it appears that the dust exposure is often higher than the limit value of 5 mg m−3 in MMA and gas-shielded arc welding. The exposure to chromium is usually higher than the standard of 0.05 mg m−3 for hexavalent chromium and the standard of 0.5 mg m−3 for total chromium in MMA welding of stainless steel, and the exposure to copper fumes during welding of copper is usually higher than the standard of 0.2 mg m−3 Among the gaseous contaminants NO 2 . NO and ozone, only ozone with MIG welding of aluminum gives concentrations in the breathing-zone exceeding the standard of 0.2 mg m−3 (0.1 ppm).