Optical radiation hazards of welding arcs.

Welding, a widely used industrial process, is one of the most intense artificial sources of optical radiation. Each type of welding process emits a different spectrum and intensity of optical radiation. For most processes, ultraviolet and visible radiation are the main components of the emission. Such factors as arc current, shielding gas, and base metal influence the emission spectrum. Adverse effects are confined to the skin and eyes, with welders suffering from a higher proportion of optical radiation associated eye conditions than do non-welders. Erythema is a common skin condition among welders, but conditions like skin cancer are rare. An evaluation of optical radiation from welding consists of determining an effective irradiance and a maximum permissible exposure duration, which can be very short (from seconds to minutes). Control measures include the use of screens to localize the hazards, and the use of personal protective equipment, such as protective clothing, safety spectacles, and welding helmets. Recent studies indicate that optical radiation can infiltrate into helmets and workers may be exposed to excessive levels. Overall, further investigation into adverse health effects and safety equipment design is warranted.