Safety & Compliance in Plant Operations Flashcards

Under OSHA 29 CFR 1910.147, which step must be done immediately after applying locks and tags and before starting work on a machine?

Answer: Verify isolation by attempting to operate the equipment

Verifying zero energy by trying to start the machine (then returning controls to off) confirms the isolation actually worked.

Two mechanics are working on the same conveyor drive under lockout. What is the correct lockout practice?

Answer: Each mechanic applies a personal lock, often using a group lockout hasp

Every authorized employee working on the equipment must have their own lock on the isolation point or group lockbox.

What OSHA eight-hour time-weighted average noise level triggers the requirement for a hearing conservation program?

Answer: 85 dBA

The action level of 85 dBA TWA requires a hearing conservation program with audiometric testing and protectors available.

Before entering a permit-required confined space, in what order should the atmosphere be tested?

Answer: Oxygen, flammables, toxic gases

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

What is the acceptable oxygen concentration range for safe confined space entry under OSHA?

Answer: 19.5% to 23.5%

Below 19.5% is oxygen-deficient and above 23.5% is oxygen-enriched, which raises fire risk.

A mechanic notices that a guard on a rotating shaft coupling was left off after a repair. What should happen before the equipment is returned to service?

Answer: Reinstall the guard before removing lockout and restarting

All guards must be back in place before locks are removed and the machine is re-energized.

Which document gives a chemical's hazards, required PPE, and first-aid measures under the OSHA Hazard Communication Standard?

Answer: Safety Data Sheet (SDS)

Under GHS-aligned HazCom, the 16-section SDS lists hazards, protective measures, and emergency response information.