Ear Canal Inserts (Plugs) for Arc Flash in NFPA 70E: Research

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ArcWear.com has performed testing on ear plugs in arc flash.  This testing is included in e-Hazard.com electrical safety training classes such as the Low Voltage Qualified (NFPA 70E) class and the NESC, OSHA 1910.269 Line Mechanics and Meter Technician Class.

The results are that foam does melt but some foams may not ignite easily.  Red foam tested ignited at less than 7 cal/cm² which the yellow tested didn’t ignite but did melt. The “combat style plug” below has been removed from the market.  The only plug which did not ignite or melt up to 50 cal/cm² was a custom ear plug made of silicone rubber.  The NFPA 70E standard requires ear canal inserts but we have also tested some muffs and no muff is currently rated for arc flash exposure. If covered under an arc rated hood matched to the hazard none of these forms of hearing protection should be an additional hazard so following NFPA 70E recommendations is the most prudent course of action.  For best practice use an arc ear plug or a silicone plug but assure that you have adequate protection for the hazard over all exposed skin and you should never have an issue with an ear canal insert.

See the slide from e-Hazard.com training below for examples of the plugs we tested (we did 100 ear plugs to determine the probability of ignition for the plugs.  Foam always melted but the yellow we tested did not ignite.)  ArcWear.com and e-Hazard.com do not recommend specific brands or sell PPE.  We provide this testing as a service to the industry for training purposes.  The testing is copyrighted by ArcWear.com and may only be used with permission.


Hugh Hoagland

does research and testing of PPE exposed to electrical arcs and is an arc flash expert. Hugh is a Sr. Consultant at ArcWear and Sr. Partner at e-Hazard. Read more about Hugh.

This Post Has 6 Comments

  1. Avatar

    Excellent information. I was not aware of these ratings for Hearing Protection inserts.Thank you.

  2. Avatar

    Where can I purchase the silicone ear plugs you mentioned? I am having a hard time locating them on online stores.

  3. Avatar
    Ron D

    Try an audiologist. Friend of the family was one and they made custom silicone earplugs. Used to block water or particulates. They might have the right stuff.

  4. Avatar

    Hi Hugh,
    Hope all is well!

    Any updates since 2014 to this article pertaining to Arc Rated Hearing protection?

    1. Hugh Hoagland
      Hugh Hoagland

      Thanks for the comment Steven. I have updated the article. The “combat style plug” shown has been removed from the market due to the sound protection issues, not the arc flash issues. Otherwise the update is pretty fairly minor but thanks for asking!

    2. Hugh Hoagland
      Hugh Hoagland

      Not really. No hearing protection has an arc rating but ASTM F2621 allows us to evaluate any non-FR material which is what we did with this report.

      This was on ArcWear’s nickel or the manufacturer. ArcWear, A Kinectrics Company provides finished product arc flash testing at their lab in Toronto, ON Canada.

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