Confined Space Entry Flashcards

Under OSHA 29 CFR 1910.146, when is an employee considered to have 'entered' a permit-required confined space?

Answer: When any part of the body breaks the plane of an opening into the space

OSHA defines entry as the moment any part of the entrant's body breaks the plane of an opening into the space.

Which atmospheric condition makes a confined space atmosphere hazardous under OSHA's definition?

Answer: Oxygen concentration of 24%

Oxygen above 23.5% is oxygen-enriched and hazardous because it greatly increases fire risk.

In what order should the atmosphere of a permit space be tested before entry?

Answer: Oxygen, combustibles, toxic gases

Oxygen is tested first because many combustible gas sensors need adequate oxygen to read accurately, followed by flammables and then toxics.

A permit space's only hazard is a potential hazardous atmosphere that continuous forced-air ventilation alone keeps safe. What may the employer use?

Answer: Alternate entry procedures under 1910.146(c)(5)

Alternate procedures apply when the only hazard is atmospheric and continuous forced-air ventilation alone can control it, though periodic testing is still required.

How long must the employer keep cancelled entry permits?

Answer: At least 1 year

Cancelled permits must be retained at least one year to support the annual review of the permit space program.

Which duty is the attendant NOT permitted to perform during a permit-required entry?

Answer: Entering the space to rescue an unresponsive entrant without being relieved

Attendants may not enter the space to attempt rescue unless trained and relieved by another attendant, because untrained entry rescue causes many deaths.

Why must atmospheric testing in a vertical space be done at several levels rather than only at the opening?

Answer: Gases can stratify, with heavier gases settling low and lighter gases rising

Gases of different densities stratify, so testing must cover the top, middle and bottom of the space.