Measurement of ultraviolet radiation from welding arcs.

It is well khown that welding arcs emit intense ultraviolet radiation and those who conduct welding operations or work nearby are exposed to the radiation and often suffer injuries. It is desirable to evaluate the ultraviolet radiation from the viewpoint of industrial health. But, there have been few quantitative studies of this radiation. We determined the ultraviolet effective irradiance, based approximately on the recommendation of the American Conference of Governmental Industrial Hygienists, for 14 different arc-welding operations commonly conducted in the workplaces. For most of them, the ultraviolet effective irradiance was at a hazardous level for both those who conduct welding operations and those who work near it. In comparing those welding operations, we found that the ultraviolet radiation hazards vary widely with welding operations. They increase with the diameter of wire, arc current and arc voltage when the type of welding method and the chemical composition of the welding materials are the same.