HRC HAZARD RISK CATEGORIES

Summary: The Hazard Risk Categories are derived from NFPA 70E, a safety standard that denotes these categories based on a selection of occupational duties.

Hazard Risk Catagories

The HRC (Hazard Risk Category) is established by the minimum amount of calories per square centimetre (ATPV or Cal/cm2). Any garment or garment set tested must result with a 50% probability of a 2nd or 3rd degree burn occurring to the wearer. The higher the result, expressed in ATPC or Cal/cm2, the higher the HRC level achieved.

There are five risk levels of 0, 1, 2, 3 and 4. Level 0 is where there is little or no risk, and level 4 is an highest or most dangerous level of risk. The chart below shows the 5 levels, with typical garments for each level, typical layering requirements and the minimum Arc Rating requirements for each category.

HRC Risk Categories_Web

HRC Information Chart

HRC Rating Hazard Risk Catagory Common Garments
at this level
Layer Requirements

Minimum Arc Rating
of the PPE (cal/cm2)

HRC 0 (or ARC 0)

Long Sleeve Shirt/Upper
Hearing Protection
Safety Glasses or Goggles

1 Layer 0
HRC 1 (or ARC 1) Arc Rated FR Shirt & FR
Trousers or FR Coverall,
Arc Flash Hood (12 cal) or
Arc Helmet with Arc Rated
Faceshield and Balaclava
1 Layer of PPE 4
HRC 2 (or ARC 2) Arc Rated FR Shirt/Upper &
FR Trousers or FR Coverall,
Arc Flash Hood (25 cal) or
Arc Helmet with Arc Rated
Faceshield and Balaclava
1 or 2 Layers of PPE 8
HRC 3 (or ARC 3) Arc Rated FR Shirt/Upper &
FR Trousers or FR Coverall
& Arc Flash Suit that meets
Minimum Arc Rating
Arc Flash Hood (40 cal)
2 or 3 Layers of PPE 25
HRC 4 (or ARC 4) Arc Rated FR Shirt/Upper &
FR Trousers or FR Coverall
& Arc Flash Suit that meets
Minimum Arc Rating
3 or 4 Layers of PPE 40

Please note that an appropriately Arc Helmet with Visor, and Gloves are also required.

Product Design Sketches

What is NFPA 70E?

This is the Standard for Electrical Safety in the Workplace, created by the National Fire Protection Agency in the United States. It was the first nationally recognized standard for electrical safety in the USA and was first released in 1976 in partnership with OSHA to help provide agreement on electrical safety standards. There have been several revisions over the years and it continues to be a document that ensures working areas that are safe from unacceptable risk.