An unventilated pit or depression below the floor level in a major repair garage is considered to be what location, extending up to the floor level where Class I liquids, hydrogen, natural gas, or LPG are transferred?

An unventilated pit or depression below the floor level in a major repair garage is considered to be what location, extending up to the floor level where Class I liquids, hydrogen, natural gas, or LPG are transferred?

• A. Class I, Division 1
• B. Class I, Division 2
• C. Class II, Division 1
• D. Class II, Division 2

Answer: (A)

Hazardous locations for flammable gases or vapors are classified as Class I. An unventilated pit or depression below floor level in a major repair garage creates a space where vapors from Class I liquids such as gasoline, hydrogen, natural gas, or LPG can accumulate, especially during transfers. Because the atmosphere can be present under normal operating conditions in this confined, poorly ventilated pit, it is treated as a Class I, Division 1 location. Division 1 means the hazardous atmosphere is expected to be present during normal operation or because of equipment faults, not just during unusual conditions. If the vapors only appeared under abnormal situations, it would be Division 2, but here the pit extends up to floor level where transfers occur and remains a persistent hazard. Class II and Class III locations deal with dusts and fibers, which aren’t the issue in this scenario.

Hazardous locations for flammable gases or vapors are classified as Class I. An unventilated pit or depression below floor level in a major repair garage creates a space where vapors from Class I liquids such as gasoline, hydrogen, natural gas, or LPG can accumulate, especially during transfers. Because the atmosphere can be present under normal operating conditions in this confined, poorly ventilated pit, it is treated as a Class I, Division 1 location. Division 1 means the hazardous atmosphere is expected to be present during normal operation or because of equipment faults, not just during unusual conditions. If the vapors only appeared under abnormal situations, it would be Division 2, but here the pit extends up to floor level where transfers occur and remains a persistent hazard. Class II and Class III locations deal with dusts and fibers, which aren’t the issue in this scenario.