OSHA Electric Arc Flash Protection

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Text of OSHA Electric Arc Flash Protection

  • Electric Power Generation,

    Transmission, and Distribution

    Electrical Protective Equipment

    Electric Arc Protection

  • Electric Arc Protection

  • Electric Arc Protection



  • Principle Requirements

    Assess workplace for hazards from flames or

    electric arcs

    If there is exposure, estimate incident energy

    Prohibit clothing when incident energy could ignite


    Require FR under certain conditions

    Select clothing with an arc rating greater than the

    estimated incident energy

    1910.269(l)(8) & 1926.960(g)

  • Appendix E Guidelines

    Assessment guidelines with examples

    Estimating available heat energy

    Selecting an appropriate calculation method

    Selecting reasonable input parameters (in particular, distance

    to arc and arc gap)

    Tables for single-phase arc in open air

    Selecting protective clothing and other protective


    Appendix E to 1910.269 & Subpart V

  • Assessment Guidelines Sources Sources of electric arcs

    Unguarded, uninsulated live parts

    Switches that arc in normal operation

    Sliding parts subject to faults

    Electric equipment subject to failure

    Sources of flames

    Open flames

    Ignitible material near flames or arcs

    Appendix E to 1910.269 & Subpart V

  • Assessment Guidelines Probability of Arc

    Whether conductive objects can fall on live parts

    Whether employee is inside MAD

    Whether operation of electric equipment is part of

    normal operation or occurs during servicing

    Evidence of impending failure

    Appendix E to 1910.269 & Subpart V

  • Assessment Examples

    Task Exposure

    Normal operation


    maintenance and

    no evidence of

    impending failure


    Evidence of arcing

    or overheating Yes

    Evidence of




    Servicing and

    maintenance All Yes

  • Assessment Examples

    Task Exposure

    Inspection with

    exposed live parts

    Worker outside of

    MAD and holding

    no conductive



    Worker holding

    conductive object Yes

    Worker inside MAD Yes

    Using open flames All Yes

  • Guidelines for Calculation Methods

    Appendix E to 1910.269 & Subpart V

  • Notes on Calculation Methods Heat flux calculator

    NFPA 70E Task Table

    2012 edition

    2015 edition


    v. 2.0

    v. 2.01

    Appendix E to 1910.269 & Subpart V

  • Guidelines on Arc Gap

    Appendix E to 1910.269 & Subpart V

  • Appendix E Incident-Energy Tables

    Appendix E to 1910.269 & Subpart V

  • Arc-Rated Protection

    Outer layer of clothing must be FR for incident

    energy exceeding 2.0 cal/cm2

    Arc-rated protection must cover entire body, with

    certain exceptions:

    Protection for hands (rubber gloves with protectors or, for

    exposures 14 cal/cm2, heavy-duty (12-oz) leather work


    Protection for feet (heavy work shoes or boots)

    Protection for the head under certain conditions

    1910.269(l)(8) & 1926.960(g)

  • Head and Face Protection Starts at 9 cal/cm2 for single-phase arcs in air

    Starts at 5 cal/cm2 for other exposures

    May be hard hat and face shield for these exposures:

    < 13 cal/cm2 for single-phase arc in open air

    < 9 cal/cm2 for other exposures

    For open-air, single-phase arc exposures, the required

    arc rating is reduced by 4 cal/cm2

    1910.269(l)(8) & 1926.960(g)

  • Compliance Deadlines

    Incident energy estimatesJanuary 1, 2015

    Use FR clothing when incident energy exceeds 2.0

    cal/cm2April 1, 2015

    Arc-flash protectionApril 1, 2015

    Everything elseJuly 10, 2014