NFPA 70E Important Definitions questions
and answers 2025\2026 A+ Grade
ATPV
- correct answer Arc Thermal Performance Value-The incident energy (cal/cm^2) on a material or a
multilayer system of materials that results in a 50 percent probability that sufficient heat transfer
through the tested specimen is predicted to cause the onset of a second degree skin burn injury based
on the Stoll curve (Definition taken from ASTM F1959/F1959M)
Cal/cm^2
- correct answer Calories per square centimeter
Electrically Safe Work Condition
- correct answer When the power has been turned off
Arc Flash Boundary
- correct answer When an arc flash hazard exists, an approach limit from an arc source at which the
incident energy equals 1.2 cal/cm^2 (One second exposure likely causes second degree burn)
Tables 130.7(C)(15)(a) & 130.7(C)(15)(b)
Limited Approach Boundary (120V)
- correct answer Table 130.4 (D)(a) [AC]. 3 ft 6 in
Restricted Approach Boundary (120V)
- correct answer Table 130.4 (D)(a) [AC]. 1 ft
Hierarchy of Risk Control
- correct answer 1.Elimination 2.Substitution 3.Engineering controls 4.Awareness 5.Administration
controls 6.PPE (See Table F.3 in NFPA 70E)
and answers 2025\2026 A+ Grade
ATPV
- correct answer Arc Thermal Performance Value-The incident energy (cal/cm^2) on a material or a
multilayer system of materials that results in a 50 percent probability that sufficient heat transfer
through the tested specimen is predicted to cause the onset of a second degree skin burn injury based
on the Stoll curve (Definition taken from ASTM F1959/F1959M)
Cal/cm^2
- correct answer Calories per square centimeter
Electrically Safe Work Condition
- correct answer When the power has been turned off
Arc Flash Boundary
- correct answer When an arc flash hazard exists, an approach limit from an arc source at which the
incident energy equals 1.2 cal/cm^2 (One second exposure likely causes second degree burn)
Tables 130.7(C)(15)(a) & 130.7(C)(15)(b)
Limited Approach Boundary (120V)
- correct answer Table 130.4 (D)(a) [AC]. 3 ft 6 in
Restricted Approach Boundary (120V)
- correct answer Table 130.4 (D)(a) [AC]. 1 ft
Hierarchy of Risk Control
- correct answer 1.Elimination 2.Substitution 3.Engineering controls 4.Awareness 5.Administration
controls 6.PPE (See Table F.3 in NFPA 70E)
