CAT 1, CAT 2, CAT 3 and CAT 4: What’s the Difference?
Time：2026/09/10 16:42:13
CAT 1, CAT 2, CAT 3, and CAT 4 are PPE categories commonly used under NFPA 70E for arc flash protection. The higher the category, the higher the minimum arc rating required.
| PPE Category |
Minimum Arc Rating |
Typical Work Scenarios |
|
CAT 1 |
4 cal/cm² |
Inspection and routine maintenance |
|
CAT 2 |
8 cal/cm² |
Panel work and electrical maintenance |
|
CAT 3 |
25 cal/cm² |
Switchgear and power distribution work |
|
CAT 4 |
40 cal/cm² |
High-energy switchgear and substation work |
CAT refers to the required PPE category, while ATPV is the tested arc rating of a garment, expressed in cal/cm². For example, a garment with an ATPV of 11 cal/cm² exceeds the minimum requirement for CAT 2.
Important: These examples are for general reference only. The required PPE should always be determined based on the arc flash hazard assessment, job task, and applicable safety standards.
The right PPE should always be selected based on the workplace hazard, applicable standards, and required level of protection—not simply by choosing the highest CAT level.
