Personnel responsible for electrical safety should stay up to date on the latest OSHA standards and all relevant consensus standards. Four major industry standards that address electrical safety as it applies to arc flash hazards are:

• OSHA standards

  OSHA regulations make it clear that, with very few exceptions, equipment must be deenergized before employees work on or near it.

  When employers must make exceptions to the above, the regulations also make it clear that it is the employer's responsibility to evaluate the workplace for hazards and protect workers from these hazards. This requires:

  • A hazard/risk assessment for the electrical hazards associated with energized work
  • selection of appropriate personal protective equipment (PPE)

• NFPA 70E

  OSHA standards don't provide details on how to conduct an electrical hazard assessment or how to select PPE. For guidance on compliance, you need to look to national consensus standards.

  NFPA 70E, Standard for Electrical Safety in the Workplace, developed by the National Fire Protection Association, is one of the foremost consensus standards for electrical safety. It covers employee protection from the electrical hazards of shock, arc flash and arc blasts.

  Although it is only referenced in OSHA 29 CFR Part 1910 Subpart S, Appendix A, NFPA 70E is considered by OSHA to be the recognized industry practice for electrical safety.

  In its standard interpretation of the relevance of NFPA 70E, OSHA states:

  Industry consensus standards, such as NFPA 70E, can be used by employers as guides to making the assessments and equipment selections required by the standard. Similarly, in OSHA enforcement actions, they can be used as evidence of whether the employer acted reasonably.

  And while the 2004 edition of NFPA 70E emphasizes that working on live parts is "the last alternative work practice," it contains extensive requirements for "working on or near electrical conductors or circuit parts that have not been put into an electrically safe work condition." When such work is to be performed, the required electrical hazard analysis has specific requirements for analysis of shock and flash hazards. Other sections provide guidance on selecting the proper PPE.

• CSA Standard CSA-Z462

  As a result of recent developments involving issues with arc flash in Canada, CSA has formed a committee to create a Canadian standard — designated CSA-Z462, Standard on Workplace Electrical Safety — to be effective in 2008.

  Based on an agreement with the NFPA, the CSA will be using NFPA 70E as the "seed document" for the development of CSA-Z462. The intent is to harmonize both documents as much as practicable for Canadian workplaces.

  In response to requests from Canadian industry for a simple summary of the direction and purpose of CSA-Z462, the CSA has created a fact sheet. For additional information, go to the CSA website at www.csa.ca.

• IEEE Standard 1584

  As implied by its title, Guide for Performing Arc Flash Hazard Calculations, IEEE Standard 1584 provides techniques for designers and facility operators to apply in determining the arc flash-protection boundary and arc flash incident energy for PPE selection.

• NFPA 70, National Electrical Code®

  While the National Electrical Code (NEC) has traditionally addressed proper installation techniques intended to prevent fire, electrocution and shock hazard, it now contains requirements related to arc flash hazards.

  Section 110-16, Flash Protection, new in the 2002 edition of the NEC, requires markings on switchboards, panelboards, industrial control panels and motor control centers to warn qualified persons of potential arc flash hazards.