When it comes to protective clothing, keeping track of the many standards, terms, and abbreviations can be challenging. One question we commonly receive is: what is the difference between arc-rated (AR) clothing and flame resistant (FR) clothing?
Scott Margolin, our resident technical expert, explains the subtle but important difference:
Luckily, the answer is simple: all arc-rated clothing is flame resistant, but not all flame resistant clothing is arc rated because some flame resistant fabrics have not been tested for exposure to an electric arc. If you have a flash fire hazard in addition to arc flash, the good news is that your AR clothing is FR, too. However, you’ll want to ensure that it has also been manikin tested for flash fire exposure (ASTM F-1930).
The term “arc rated” comes from NFPA 70E, Standard for Electrical Safety in the Workplace, which provides safety-related guidance from workplace electric arc hazards associated with “installation, inspection, operation, maintenance, and demolition of electric conductors, electric equipment, signaling and communications conductors and equipment, and raceways” (source: NFPA 70E-15, 90.2(A)).
According to NFPA 70E, the term “arc rated” applies to the shirts, pants, coveralls, jackets, parkas, and rainwear worn by workers who face the risk of momentary electric arc and related thermal hazards as part of their normal work environment (130.7(C)(9) Informational Note; emphasis added).
The expression “arc rating” has been in common use for several decades, but the abbreviation “AR” first entered code in the 2012 edition of NFPA 70E. Informational Note No. 1 under the Chapter 100 definition for “Arc Rating” explains, “Arc-rated clothing or equipment indicates that it has been tested for exposure to an electric arc. Flame-Resistant (FR) clothing without an arc rating has not been tested for exposure to an electric arc.”
The 2015 edition clarified, in the same note, that “all arc-rated clothing is also flame resistant.”
So all arc-rated clothing is flame resistant, but not all flame resistant clothing is arc rated because some flame resistant clothing has not been tested for exposure to an electric arc.
Simply stated, if your flame resistant clothing has an arc rating, it is arc-rated. If you face an electric arc hazard, wear flame resistant clothing that has an arc rating.
As both a manufacturer and a distributor, Tyndale offers the industry’s largest selection of arc-rated flame resistant clothing. Browse our selection today!
Stumped by an NFPA 70E AR or FR clothing question? Let Tyndale’s resident expert help! Take advantage of Tyndale’s limited-time offer for a complimentary 15-minute consultation with Scott Margolin, our Vice President of Technical and a recognized industry expert.