An arc flash can be started by several causes. Some of these, like accidental contact and dropping tools are avoided by just not opening up energized equipment. Arcs can initiate from tracking across insulators, most commonly seen in high voltage equipment and caused by surface contamination on the insulators. Corrosion can increase the resistance of connections and cause extreme heating or lead to mechanical failure. Unsafe work practices is one of the more significant causes because they are avoidable. Many times this is caused by just trying to do things too quickly or without thinking things through; “cutting corners;” or not following proper lock-out/tag-out procedures.
Arc flash injury is best avoided by not working on energized electrical equipment. Sometimes this is not possible. In those cases the work must be performed by trained qualified workers and following the completion of a hazard risk analysis.