Page 45 - Occupational Health & Safety, February 2017

Hazard Risk Category (HRC)
Category 0 Category 1 Category 2 Category 3
Category 4
Required Minimum Arc Rating of PPE
> 2 cal./cm2 4 cal./cm2
8 cal./cm2 25 cal./cm2
40 cal./cm2
Clothing Description
Non-melting flammable materials, glasses/face shield, leather gloves over rubber Fire Resistant (FR) shirt and FR pants, or FR coverall (1 layer)
FR shirt, FR pants (1 or 2 layers) and cotton underwear
FR shirt and FR pants, plus FR coverall and cotton underwear OR FR coverall
(2 or 3 layers)
FR shirt, FR pants, multi-layer flash suit, cotton underwear
Thermal Protective Value (ATPV).
HRC is the safety standard that shows the minimum amount of
PPE protection a worker needs based upon the potential exposure to a hazard he or she might experience. HRC categories range from 0 to 4, with 4 being the highest risk.
The other important number that is critical in choosing the right PPE is Arc Thermal Protective Value (ATPV). ATPV is the incident energy level (measured in cal./cm2) that would cause a second-degree burn.
The HRC and ATPV are determined through a flash hazard analysis that studies all the electrical circuits in the device capable of being energized and determines how much energy would be released in case of an arc flash. Once you identify the potential ex- posure of your task, you can then find the ATPV for that task. The ATPV leads you to the appropriate HRC level. (See the chart in this
article.) ASTM F1506 is the standard that determines the HRC of a glove. ASTM P S58 is the standard that determines ATPV.
With more arc flash gloves available today, you have even more options to choose from—seamless knit gloves that are more dex- terous than traditional rubber, coated gloves with enhanced grip, gloves with FR-treated TPRs on the back of the hand.
As long as you understand your critical numbers—HRC and ATPV for your task at hand—and choose the right level of protec- tion for the job, arc flash gloves are more comfortable and protec- tive than ever. Most important, you should always work with your safety specialist to make sure that you wear the appropriate PPE for your job.
Amanda Green is Product Development Manager at West Chester Protective Gear.
wwwU.notihtlesdo-4nli1ne.com
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