Hazard Risk Category (HRC) was a term used by NFPA 70E to refer to levels of protection required for various job applications. In the updated 2015 NFPA 70E Standard this term was changed to “Arc Flash PPE” and HRC was removed from the standard.
One thing that hasn’t changed is our use of HRC for arc resistant garments. We will continue to use this familiar term to assist our customers with quickly identifying what level of protection our PPE clothing meets.
|ARC FLASH REQUIRED
|HRC LEVEL 1
|HRC LEVEL 2
|HRC LEVEL 3
|HRC LEVEL 4
WHAT IS THE DIFFERENCE IN FLAME RESISTANT (FR) AND ARC RATED (AR) FABRIC?
Scan the QR code above to see how FR reflective trim and Non-FR reflective trim react when an ignition source is removed.
This is a great question that is often asked by customers. The simple answer is: All arc rated fabrics are flame resistant. However, all flame resistant fabrics are NOT arc rated. The long answer is a bit more complicated and revolves around textile and garment testing standards.
In order to be considered flame resistant, the fabric must not melt or drip and cannot exceed the char length (per ASTM F1506, less than 6”; per NFPA 2112, less than 4”) or afterflame time when tested according to ASTM D6413. This test method measures the vertical flame resistance of fabrics. According to specifications for flame resistant fabrics and garments, once the ignition source has been removed the fabric must self-extinguish, cannot melt or drip, and the char length cannot exceed the specific test specification. This test is perfect to establish if a fabric is flammable (will catch on fire and/or will melt and/or drip) or flame resistant (self-extinguishes) in a controlled test setting. Scan the QR code to the left to see how FR reflective trim and Non-FR reflective trim react when an ignition source is removed.
Arc rated (AR) fabrics are tested to ASTM 1959, which requires any fabric submitted for testing to be flame resistant. This test method is a bit more complicated, and is used to measure and describe the properties of fabrics in response to convective and radiant energy generated by an electric arc under controlled laboratory conditions. By simulating an electric arc, the test measures the incident energy on a fabric that results in a 50% probability of the on-set of second-degree skin burn injury. Arc ratings can be reported as ATPV (Arc Thermal Performance Value) or EBT (EBT Breakopen Threshold Energy).