Arc-rated clothing is rated in which unit?

Arc-rated clothing is rated in which unit?

• A. Cal/Cm2
• B. J/cm2
• C. Watts
• D. Degrees

Answer: (A)

Arc-rated clothing is described by how much heat energy per unit area the fabric can withstand from an arc flash. That rating uses calories per square centimeter (cal/cm^2) because it expresses energy density, indicating the incident energy the fabric protects against before causing a burn or ignition. This is the standard unit used in PPE ratings. The other options don’t fit: watts is power, degrees is temperature, and joules per square centimeter is not the industry-standard unit (though it’s related by 1 cal ≈ 4.184 J).

Arc-rated clothing is described by how much heat energy per unit area the fabric can withstand from an arc flash. That rating uses calories per square centimeter (cal/cm^2) because it expresses energy density, indicating the incident energy the fabric protects against before causing a burn or ignition. This is the standard unit used in PPE ratings. The other options don’t fit: watts is power, degrees is temperature, and joules per square centimeter is not the industry-standard unit (though it’s related by 1 cal ≈ 4.184 J).