This table was taken from the NFPA 70E -2004, "Standard for Electrical Safety in the Workplace" Table 130.7(C)(11) Protective Clothing Characteristics.

 Hazard/Risk Category

Clothing Description

(Typical number of clothing layers given in parentheses)

Required Minimum

Arc Rating of PPE cal/cm2

0   Non-melting, flammable materials (i.e., untreated cotton, wool,  rayon,  silk, or blends of these materials) with a fabric weight at least 4.5 oz/yd2 (1) N/A
1  

FR shirt and FR Pant or

FR coverall (1)

 

4
2

 

Cotton underwear - conventional short sleeve and brief/shorts, plus FR shirt and FR pants (1 or 2)

 

8
3

 

Cotton underwear plus FR shirt and FR pant plus FR coverall, or cotton underwear and two FR coveralls. (2or3)

 

25
4  

Cotton underwear plus FR shirt and FR pant plus

multilayer flash suit (3 or more)

 

40