The term may contain hazardous atmosphere under abnormal conditions is regarding to what federal standard?

• A. Confined space
• B. Enclosed space
• C. Permit-required confined space
• D. Hazardous area

Answer: (B)

The concept being tested is OSHA’s classification of spaces that may contain a hazardous atmosphere. Under the OSHA confined spaces rule, a space is considered permit-required confined if it may contain a hazardous atmosphere, even under abnormal conditions. That potential hazard triggers special controls: a written permit, atmospheric testing, ventilation, isolation of hazards, and trained attendants. This definition appears in 29 CFR 1910.146, the Permit-Required Confined Space standard. General confined spaces do not automatically require a permit, and terms like enclosed space or hazardous area are not the formal OSHA classifications used here.