Which regulation is OSHA's Confined Space standard?

• A. AFMAN 91-203 Chap. 23 (USAF)
• B. ANSI Z117.1
• C. AFI 48-151
• D. 29 CFR 1910-146 (OSHA)

Answer: (D)

Confined-space entry is governed by an enforceable regulatory framework, not just guidance documents. The rule that directly prescribes how to handle permit-required confined spaces in general industry is codified as 29 CFR 1910.146. This regulation defines what counts as a permit-required confined space, requires an entry permit, and lays out the responsibilities of entrants, attendants, and supervisors. It also covers atmospheric testing, ventilation, rescue planning, training, and the overall program elements needed to ensure safe entry operations.

ANSI Z117.1 is a widely used guidance standard, and AF manuals or instructions pertain to specific organizations, but neither replaces OSHA’s binding regulation. That makes 29 CFR 1910.146 the correct, best answer.