Electrical Explosion in Warehouse Causes Significant Burns

This case involves a man who was injured while attempting to perform electrical work for a large warehouse owned by an international logistics company. The man was working in a confined area in the lower level of the building and had to crawl through a small opening in order to reach the breaker room. In order to access the breaker area, the man used a metal wrench to remove a few bolts from an access panel. After the man entered the room and stood up there was a massive electrical explosion. During the explosion, the worker suffered significant burns to his body and face.

Question(s) For Expert Witness

1. For how long have you been performing electrical maintenance work on commercial buildings?

2. What factors might lead to an explosion like the one in this case?

Expert Witness Response E-001181

I have 25+ years of experience in developing and reviewing safe electrical maintenance procedures for government and industrial/commercial applications. During that time, I've also been heavily involved in performing forensic investigations on electrical mishaps. I am the author/co-author of several manuals, publications and standards on this topic. I've been engaged in devising/reviewing maintenance procedures with an emphasis on safety and investigating electrical mishaps throughout my career. At face value, the description of the case is a classic arc flash matter, where a short circuit in the panel causes an electrical arc, leading to an explosion. Arc flash can occur without actuating the circuit breakers if internal clearances in the panels are inadequate, for example. There are other possibilities, such as explosive dust/gas environment, as well. A possible significant OSHA/electrical code violation concerning access clearances exists based on the description of the case. I've worked on several arc flash/electric shock matters involving electrical panels in commercial facilities and maintenance work.