Will layering of ATPV rated clothing achieve a higher ATPV rating and how does it affect the Total System Arc Rating?

PPE And Layering...Total System Arc Rating

Let’s discuss electrical specific Personal Protective Equipment (PPE) for arc flash protection. This article will talk about what layering means to your personal protection. We’re talking about the cal/cm2 rating of protective clothing, and its Arc Thermal Performance Value (ATPV).

Have you mixed two layers of ATPV rated clothing from two different clothing manufacturers (i.e. inherently FR and chemically treated cotton) to achieve a higher ATPV rating? You can’t just add up the ATPV values on the collar tag of arc flash protection clothing to achieve a higher level of protection. If you have been doing this, you need to stop and re-evaluate your electrical specific PPE requirements for arc flash protection.<!--break-->

Layering of FR clothing with ATPV ratings to achieve a higher level of arc flash protection is an effective control measure against burns related to arc flash when de-energization is not possible. But, layering of ATPV rated clothing to achieve a Total System Arc Rating, can only be done when the layered clothing, as will be worn, is tested in a multi-layered arc test to ASTM 1959-06.

So, make sure you ask the supplier of your arc flash protective clothing for the American Society for Testing and Materials (ASTM) 1959-06 test results for the ounce weight of the cloth used in the pants, shirts, coveralls, arc flash suits, jackets, balaclavas, etc., as a single layer and the multi-layered system you may use. Total System Arc Rating is the overall rating of a combination of layers of clothing that have been tested to an approved standard. You may have thought that you could just add the two ATPV values of two pieces of FR clothing when layering arc flash protection, but this is not the case!