What is the Difference Between Arc-Rated and Flame-Resistant?

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What is the Difference Between Arc-Rated and Flame-Resistant?

Arc-rated and flame-resistant: are those the same thing?

Confusion on the difference between an arc-rated (AR) garment and a flame-resistant (FR) garment still exists.

Let’s make the terms “arc-rated” and “flame-resistant” a bit simpler to understand.

Change in the Language

The language concerning the labeling of personal protective equipment (PPE) changed in the 2012 NFPA 70E. What people had previously referred to as FR was now called AR. 

Here’s the reasoning:

  1. ALL clothing with an arc rating is FR
  2. NOT all FR clothing has an arc rating

FR clothing may reduce burn injuries if they meet the proper standards (such as NFPA 2112, 1971 or 1977 or ASTM F2733). But not all PPE that claims to be “FR” really has the right rating.

Change in Testing

The evolution of FRC has followed a route to better and more nuanced protection.

We like to think of it like this: At first, “FR” PPE was for fire fighters and a few work applications. The flame-resistant PPE initially was designed to be “non-contributory,” to provide minimal OSHA compliance and to help avoid a lawsuit for not providing PPE when flame was present. This type of compliance helped companies comply with US OSHA 1910.132, PPE hazard assessment requirements.

These guidelines provide a framework to REQUIRE PPE.  But they give no guidance on the level needed.

Starting in firefighting, “FR” became protectively engineered. Time-to-burn testing was added to vertical flame testing. These, along with flash fire mannequins and, finally, arc flash testing, progressed to assist in “matching the PPE to the hazard.”

During the 1990’s, this protective engineering really progressed in standardization in the US when two things happened:

  1. NFPA 2112 rated garments for a specific level of flash fire [I like to call this Flash Fire Rated (FFR)] 
  2. ASTM F1506 added the ASTM F1959 test to arc flash PPE to make it Arc Rated (AR).

These large scale tests aren’t perfect. They are correlative, though, to many hazards. They have proven to reduce worker injury from burns quite dramatically, leading to about a 60% drop in fatalities in electrical incidents and good progress in flash fire incidents, including petrochemical and combustible dust applications.

Legislative Change

Only in the 2000’s did we start getting better legislative guidance with the following standards:

–US OSHA Oil and Gas Compliance Directive requiring NFPA 2112 or equivalent for some applications

–Electric utility GT&D (OSHA 1910.269) AR PPE requirements to “match to the hazard” in 2015

Change in NFPA 70E

In 2000, NFPA 70E really changed the climate by requiring certain levels of AR clothing and requiring them to meet arc rating standards. (ASTM F1506 and ASTM F1959 are just a couple of examples.) 

Before receiving an arc rating, the clothing must have already been tested to be flame-resistant. Garments labeled AR have met a level of protection against burn injury based on testing of the garment or the material itself.

Choosing the Correct PPE

A point often brought up in our arc flash and electrical safety training is the need for checking the garment label before use. The label lists the appropriate standard that garment has met for an arc flash hazard.

This information is important to know when choosing PPE for your workers. Workers need to wear the correct PPE around the hazard identified . As stated on Arcwear’s FAQ page:

When making purchasing decisions for your workforce, keep in mind all Arc Rated and Flash Fire Rated fabrics are flame resistant, but not all FR fabrics have an appropriate rating. Be aware of companies attempting to use outdated standards (FTMS 191A.5901 or FTMS 191A.5903) or standards with no pass/fail criteria (ASTM D6413) in their testing or even standards not designed for clothing (NFPA 701). Paying careful attention to labels and testing procedures to ensure your PPE has an arc or flash fire rating will increase the level of protection you provide to your employees.

Need more technical details?

Read this ArcWear blog, Back to Basics: What Does FR Mean? It also explains the difference between flame-resistant and fire retardant. 

Have a question about electrical safety and standards?   

Author

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 2 Comments

  1. hedayat shariatimehr

    hi
    thanks for your advise
    I am a safety officer in oil and gas refinery . how we can introduce method for testing fabric or clothing in our workplace?

    1. Hugh Hoagland

      Purchase rating fabric from a reputable manufacturer. Arc testing is destructive and cannot be performed by an end user.

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