Ultraviolet radiation emitted by CO2 arc welding

The arcs associated with arc welding emit high levels of ultraviolet radiation (UVR), and this often causes acute injuries In the workplace, particularly photokeratoconjunctivitis. It is important to know the level of UVR emitted by are welding under various conditions, as this information will help in evaluating potential UVR hazards in welding workplaces and taking protective measures against it. In this study, the ACGIH effective irradiance for UVR was measured experimentally for CO2 are welding in order to evaluate its UVR hazards. A welding robot was used in the experiment in order to realize reproducible and consistent welding operations. The effective Irradiance at 1 m from the arc was in the range 0.28-7.85 W/m(2) (28-785 muW/cm(2)) under the study conditions. The corresponding permissible exposure time per day is only 4-100 s, suggesting that UVR from CO2 are welding is actually hazardous for the eye and skin. It was found that the effective irradiance is inversely proportional to the square of the distance from the arc, is strongly dependent on the direction of emission from the arc with a maximum at 50-60 degrees from the plate surface, and tends to increase with welding current. (C) 2001 British Occupational Hygiene Society. Published by Elsevier Science Ltd. All rights reserved.