CPM Safety & Compliance in Plant Operations 2 — Questions and Answers
Question 1: Under OSHA 29 CFR 1910.147, which step must be done immediately after applying locks and tags and before starting work on a machine?
- Notify the plant manager in writing
- Verify isolation by attempting to operate the equipment (Correct answer)
- Remove the machine guards
- Bleed the hydraulic reservoir to empty
Correct 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.
Question 2: Two mechanics are working on the same conveyor drive under lockout. What is the correct lockout practice?
- One lock is enough if both mechanics agree
- Each mechanic applies a personal lock, often using a group lockout hasp (Correct answer)
- The supervisor's lock covers both workers
- Only a tag is needed when two people are present
Correct 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.
Question 3: What OSHA eight-hour time-weighted average noise level triggers the requirement for a hearing conservation program?
- 80 dBA
- 85 dBA (Correct answer)
- 90 dBA
- 95 dBA
Correct answer: 85 dBA
The action level of 85 dBA TWA requires a hearing conservation program with audiometric testing and protectors available.
Question 4: Before entering a permit-required confined space, in what order should the atmosphere be tested?
- Toxic gases, flammables, oxygen
- Flammables, oxygen, toxic gases
- Oxygen, flammables, toxic gases (Correct answer)
- Any order is acceptable
Correct 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.
Question 5: What is the acceptable oxygen concentration range for safe confined space entry under OSHA?
- 16.0% to 21.0%
- 19.5% to 23.5% (Correct answer)
- 20.9% to 25.0%
- 18.0% to 22.0%
Correct answer: 19.5% to 23.5%
Below 19.5% is oxygen-deficient and above 23.5% is oxygen-enriched, which raises fire risk.
Question 6: 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?
- Run it briefly to confirm alignment, then reinstall the guard
- Post a warning sign and keep running
- Reinstall the guard before removing lockout and restarting (Correct answer)
- Notify operators to stay clear of the coupling
Correct 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.
Question 7: Which document gives a chemical's hazards, required PPE, and first-aid measures under the OSHA Hazard Communication Standard?
- Bill of lading
- Safety Data Sheet (SDS) (Correct answer)
- Certificate of analysis
- Job hazard analysis
Correct answer: Safety Data Sheet (SDS)
Under GHS-aligned HazCom, the 16-section SDS lists hazards, protective measures, and emergency response information.
