Electrical safety in arc welding processes

Manual metal arc welding can be a hazardous practice if proper precautions are not taken. The welding procedure uses an open electric arc between an electrode and the metals to be joined. Besides the obvious risks of burns and inflammation of the cornea, which are prevented by using proper personal protective equipment, the operator may also be subject to the risk of electric shock from the exposed parts of the welding circuit, both the electrode and the workpiece. In addition, the welding current, by straying from the intended path, can cause localized heating of parts, with the risks of triggering fires and/or explosive atmospheres. Because of the high current required by the arc welding equipment, operators are exposed also to strong electromagnetic fields. This paper seeks to clarify the aforementioned issues, especially in light of the fact that the risk associated with electric shocks may be unknown to welders and their supervisors.