Arc flash protective clothing with a rating of 4 cal/cm2 is intended for which hazard risk category?

Arc flash protective clothing with a rating of 4 cal/cm2 is intended for which hazard risk category?

• A. 2
• B. 0
• C. 10
• D. 4

Answer: (D)

PPE for arc flash is chosen by matching the incident energy to the garment’s arc rating. The arc rating, given in cal/cm2, tells you the maximum energy the fabric and seams can withstand without burning or melting. A garment rated at 4 cal/cm2 is intended to protect against incident energy up to 4 cal/cm2, which places it in hazard risk category 4. In practice, you pick PPE with a rating that meets or exceeds the estimated energy at the work location; if the energy could be as high as 4 cal/cm2 or more, you’d use category 4 gear. Lower energy (near 0-2 cal/cm2) would call for lower categories, while higher energy exposures require higher categories (e.g., 10 cal/cm2 or more).

PPE for arc flash is chosen by matching the incident energy to the garment’s arc rating. The arc rating, given in cal/cm2, tells you the maximum energy the fabric and seams can withstand without burning or melting. A garment rated at 4 cal/cm2 is intended to protect against incident energy up to 4 cal/cm2, which places it in hazard risk category 4. In practice, you pick PPE with a rating that meets or exceeds the estimated energy at the work location; if the energy could be as high as 4 cal/cm2 or more, you’d use category 4 gear. Lower energy (near 0-2 cal/cm2) would call for lower categories, while higher energy exposures require higher categories (e.g., 10 cal/cm2 or more).