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Sunday, June 21, 2009
NFPA 70E It’s Now Effective. Is Your Program

On August 13, 2007, the revisions for the OSHA Electrical Installation Standard, Subpart S, 29CFR 1910.302-308, which were issued on February 14, 2007, became effective. This standard was last updated in 1981. What are the major changes and how might they affect you?

While there was no change to these OSHA standards from 1981 to 2007, there were substantial changes in the National Fire Protection Association (NFPA) standards. The NFPA is the organization that generates the National Electrical Code (NEC). Primary among the changes was the issuance of NFPA 70E: Standard for Electrical Safety in the Workplace, 2004. This standard includes requirements for employers to develop programs, procedures and work practices, and to supply appropriate personal protective equipment (PPE) to protect employees against electrical shock and arc flash hazards.

Key concepts in this standard include:

  • Shock hazard analysis
  • Flash hazard analysis
  • Shock protection boundaries
  • Flash protection boundaries

Why did the NFPA feel the need to generate this standard? Between five and 10 serious arc flash/blast hazards occur each day in the United States. The NFPA felt that selecting and using appropriate arc flash clothing and equipment could prevent the injuries and fatalities associated with arc flash/blast. It also believed that selecting and using the appropriate insulating equipment could prevent the injuries and fatalities associated with electrical shock.

NFPA 70E: It’s Now Effective. Is Your Program?The standard requires that a flash hazard and a shock hazard analysis be done before a person approaches any exposed electrical conductor or circuit part that has not been placed in an electrically safe work condition. The shock hazard analysis determines the voltage to which personnel will be exposed, boundary requirements, and the PPE necessary to minimize the possibility of electrical shock. The shock protection boundaries identified as Limited, Restricted, and Prohibited Approach Boundaries are applicable to situations in which approaching personnel are exposed to live parts. Where it has been determined that work will be performed within the flash protection boundary, the employer shall document the incident energy exposure of the worker. This incident energy exposure level shall be based on the working distance of the employee’s face and chest area from a prospective arc source for the specific task to be performed. Flame-resistant (FR) clothing and PPE shall be used by the employee based upon the exposure associated with the specific task. As an alternative, the PPE requirements can be determined based upon the task to be performed, as shown in Table, Hazard Risk Category Classification, of the standard.

No qualified person shall approach or take any conductive object closer to live parts than the restricted approach boundary unless:

  • The qualified person is insulated or guarded from the live parts (insulating gloves or insulating gloves and sleeves are considered insulation only with regard to the energized parts that are being worked on) and no un-insulated part of the person’s body enters the prohibited space, or
  • The live part is insulated from the qualified person and from any other conductive object at a different potential, or
  • The qualified person is insulated from any other conductive object during bare-hand live-line work.

NFPA 70E: It’s Now Effective. Is Your Program?Unqualified persons shall not be permitted to enter spaces that are accessible to qualified employees only, unless the electrical conductors and equipment involved are in an electrically safe work condition. Where any unqualified person is working at or close to the limited approach boundary, the designated person in charge of the work space where the electrical hazard exists shall cooperate with the designated person in charge of the unqualified persons to ensure that all work can be done safely. This shall include advising the unqualified persons of the electrical hazard and warning them to stay outside of the limited approach boundary.

There are numerous other requirements and details in this standard, including the need to develop and use Electrical Energized Work Permits. OSHA has not formally compared each provision of the NFPA 70E-2004 standard with the parallel provision in Subpart S but generally believes the NFPA standard offers useful guidance for employers and employees attempting to control electrical hazards.

For additional detail, see the standard or contact Colin J. Brigham, CIH, CSP, CPE, CPEA, at 610.524.5525, ext. 24, or email.