Let’s make the terms “arc-rated” and “flame-resistant” a bit simpler to understand.
The language concerning the labeling of personal protective equipment (PPE) changed in the 2012 NFPA 70E. What people had referred to as FR in years previous was now called AR. Here’s the reasoning:
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.
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,” provide minimal OSHA compliance and 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 but these guidelines provide a framework to REQUIRE PPE but no guidance on the level needed.
Starting in firefighting, the “FR” became protectively engineered. Time to burn testing was added to vertical flame testing and these along with flash fire mannequins and finally arc flash testing progressed to assist in “matching the PPE to the hazard.” This protective engineering really progressed in standardization in the US in the 1990’s when NFPA 2112 rated garments for a specific level of flash fire (I like to call this Flash Fire Rated [FFR]) and 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 and 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.
Only in the 2000’s did we start getting better guidance legislatively 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
In 2000 NFPA 70E really changed the climate requiring certain levels of AR clothing and requiring it to meet arc rating standards (ASTM F1506 and ASTM F1959 are just a couple of examples). Before doing that, it 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.
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. The correct PPE must be worn 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.
The full explanation on the ArcWear site contains the testing requirements in more detail. It also includes an explanation on flash fire rating (FFR).