50-V Shock Hazard Threshold

For the last few years, much attention has been focused on arc flash hazards by the electrical community; however, statistics indicate that the majority of electrical injuries and fatalities are the result of shock. The Occupational Safety and Health Administration and NFPA 70E
Standard for Electrical Safety in the Workplace
both require electrical conductors and circuits that operate at 50 V or greater to be de-energized before working on or near those conductors or circuits. This requirement is generally interpreted to mean that a shock hazard does not exist below 50 V. The objective of this paper will be to explore the validity of this assumption and to determine whether there may be a more appropriate level at which de-energizing should be considered.