Ignition of Welding Arc and UV Actinic Hazard Evaluation

Welding arcs emit strong ultraviolet (UV) radiation, which could pose serious health risks for skin and eyes. According to Directive 2006/25/EC, UV hazard evaluation has to be performed in the working environment. The measurement of welding arc ignition radiation is a difficult task. This article describes the effort made to determine actinic radiant exposure levels during welding arc ignition in the controlled environment of a welding laboratory. A new method of UV actinic hazard evaluation from welding arc ignition radiation using a CCD spectroradiometer combined with a photometer is presented. The hazard of UV emitted in pulsed metal active gas welding (MAG-P) of construction steel is described. The duration of ignition peak in the study was in the range of 9–15 ms. The actinic radiant exposure during arc ignition over aversion response time was in the range of 0.26–1.12 J/m2. The daily exposure time can easily exceed the permissible exposure time obtained in our study, i.e., 13–34 s, which means that UV radiation form MAG-P arc welding is hazardous for workers in the vicinity of the welding arc. The measurement method presented in the article enables determination of radiant exposure of arc ignition radiation.