In 1910.137 it talks about the Personal Protective Equipment that can be used while working with electricity. When looking at a hard hat a Type II Class E is the one you need for head protection against electricity. Another is thick rubber gloves that are rated for the electricity that you are working on. On the side of the glove it will have a voltage rating, the glove will only protect up to the voltage that is on the glove and nothing higher.
Causes of electrocution fatalities vary. Some are with contact with overhead power lines. Contact with live circuits is a common one. Not following lock out tag out procedures. Also poorly maintained extension cords and or defective power tools.
Lock out tag out is very important and every employee should know the rules and regulations with it. The first thing to do with is to place a tag on each disconnecting means so that t de-energizes the machine and or circuits. There all so should be a lock on these disconnects. The most important thing is that only the person who put the tag on the machine or electrical circuit can remove the lock and put the machine back in to operation.
To be able to work on electrical equipment you must receive special training. You must have safe work practices, with proper personal protective equipment. That person must know how to isolate the electric sources. They will also have the proper test equipment and tools. You must be
References: Osha.gov http://www.plantservices.com/articles/2013/01-arc-flash-history.html