< Resources

Hazard Risk Catagories

NFPA 70E is a safety standard that denotes Hazard Risk Categories (HRC) based upon an array of occupational duties. An HRC level is determined by the minimum amount of calories per square centimeter (ATPV or Cal/cm2). There exists five risk levels which range from 0 to 4. Level 0 is little to no risk whereas, level 4 is extreme risk. The following chart illustrates the five HRC levels with corresponding clothing, layer requirements and minimum arc ratings.

Hazard Risk Category Clothing Description Layerb Requirements Minimum Arc Rating of PPE (cal/cm²)
HRC 0 Long Sleeve Shirt and Pants
Hearing Protection
Safety Glasses or Goggles
1 Layer 0
HRC 1 Arc Rated FR Shirt & FR Pants or FR Coverall 1 Layer of PPE 4
HRC 2 Arc Rated FR Shirt & FR Pants or FR Coverall 1 or 2 Layers of PPE 8
HRC 3 Arc Rated FR Shirt & FR Pants or FR Coverall;
Arc Flash Suit that Meets Minimum Arc Rating;
2 or 3 Layers of PPE 25
HRC 4 Arc Rated FR Shirt & FR Pants or FR Coverall;
Arc Flash Suit that Meets Minimum Arc Rating;
3 or 4 Layers of PPE 40