A comparison of iron oxide fume inside and outside of welding helmets.

A study was conducted to compare the iron oxide fume concentrations inside and outside the helmets of welders. Airborne iron oxide fume concentrations were determined simultaneously at four body locations--the left front shoulder, right front shoulder, front chest, and inside the helmet--during welders' normal activity. Results indicate that the fume concentrations at the actual breathing zone inside helmets are reduced to 36%-71% of concentrations outside the helmets, depending on the type of welding and employees' postures.