Safety Practice Questions for Level 4 · Expert

1. Question 1

   A contractor must open a process valve for a tie-in while plant maintenance has the same valve locked closed under a separate job. Both jobs are scheduled for the same shift. What should the supervisor require before either job begins?

   1. Let each crew control the valve under its own permit
   2. Give the contractor a key to the plant lock
   3. Remove the plant lock when the contractor arrives
   4. Coordinate one isolation plan and sequence the work
   Show the answer

   Answer: D. Coordinate one isolation plan and sequence the work

   The jobs require opposite valve positions. One coordinated isolation authority and work sequence prevents either crew from changing the shared boundary while the other relies on it.

2. Question 2

   Two confined-space entries are scheduled at the same time. Four detectors are assigned, but one repeatedly fails its bump test and passes only after restart. Three verified detectors can cover one entry team and its attendant. What is the best plan?

   1. Use the restarted detector at the second entry
   2. Share one detector between both attendants
   3. Remove it and delay one entry until a verified detector is available
   4. Begin both entries and repeat the bump test hourly
   Show the answer

   Answer: C. Remove it and delay one entry until a verified detector is available

   The failed detector cannot support an entry. One entry must wait until another verified detector is available so both teams have required monitoring.

3. Question 3

   A tabletop exercise shows that two emergency pumps need the same fuel truck during a regional outage. What is the best follow-up?

   1. Add a second fuel vendor to the emergency contact list.
   2. Test alternate fuel supply and delivery order.
   3. Increase both pump run times during normal weeks.
   4. Buy a larger fuel tank for one emergency pump.
   Show the answer

   Answer: B. Test alternate fuel supply and delivery order.

   Testing alternate fuel supply and delivery priority addresses the shared dependency exposed by the exercise. A lists a vendor without proving outage delivery, C adds routine wear without protecting fuel access, and D protects only one pump while leaving the shared delivery risk unresolved.

4. Question 4

   A permit-space staffing plan assigns the attendant to enter the wet well and help repair a pump if the entrant needs help. What program correction is needed?

   1. Let the entrant approve the entry permit while the entry supervisor performs the atmospheric tests and keeps the records.
   2. Let the entry supervisor remain offsite and have the entrant cancel the permit after the repair.
   3. Have the attendant monitor entrants from outside, document atmospheric readings, and verify repair steps for two permit-space entries at once.
   4. Keep the attendant outside to monitor entrants and summon rescue, and assign inside repair to an authorized entrant.
   Show the answer

   Answer: D. Keep the attendant outside to monitor entrants and summon rescue, and assign inside repair to an authorized entrant.

   The attendant must remain outside and perform no duty that interferes with monitoring and protecting entrants. For example, the attendant cannot become a second mechanic when a pump bolt will not move. A and B shift permit control to the entrant, while C assigns documentation, repair verification, and simultaneous entries that can interfere with monitoring.

5. Question 5

   Fleet records show that every portable gas monitor passed a bump test, but several monitors have overdue calibrations. What distinction should the safety program enforce?

   1. A bump test adjusts sensor accuracy, while calibration only checks whether the alarm sounds.
   2. A bump test checks response; calibration sets accuracy to known gas.
   3. Verify alarm response with a bump test, then extend calibration until the next scheduled service.
   4. Calibration checks alarm response; a bump test sets sensor accuracy.
   Show the answer

   Answer: B. A bump test checks response; calibration sets accuracy to known gas.

   OSHA and ISEA guidance distinguish a bump test, which confirms sensor and alarm response, from calibration, which adjusts readings against known gas. Passing the bump test does not clear an overdue calibration, much like a smoke-alarm button does not measure detector accuracy. A and D reverse the jobs, while C uses a response check to extend an overdue calibration.

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