ISC Lockout/Tagout & Machine Guarding — Questions and Answers
Question 1: What is the correct first step in the typical sequence for a lockout/tagout procedure on a machine that is running?
- Apply the lock to the energy-isolating device
- Notify affected employees, then shut the machine down by its normal stopping procedure (Correct answer)
- Verify zero energy by attempting to start the machine
- Remove the tag from the previous shift
Correct answer: Notify affected employees, then shut the machine down by its normal stopping procedure
Affected employees must be notified, and the machine shut down normally before energy isolation, lock application, release of stored energy, and verification of isolation.
Question 2: Who is permitted to remove a lockout device after servicing is complete?
- Any supervisor on site
- The authorized employee who applied it (Correct answer)
- The next shift's operator
- The maintenance manager regardless of who applied it
Correct answer: The authorized employee who applied it
Each authorized employee applies their own lock and is the only one who removes it, with narrow, documented exceptions when the employer follows a specific removal procedure.
Question 3: Which of the following is considered a form of stored (residual) energy that must be released or restrained during LOTO?
- A fully discharged battery
- A compressed spring or a charged capacitor (Correct answer)
- An open breaker
- A de-pressurized hydraulic line
Correct answer: A compressed spring or a charged capacitor
Springs, capacitors, elevated loads, pressurized lines, and flywheels can all hold energy after power is isolated. That energy must be bled down, blocked, or grounded.
Question 4: Which category of machine guard prevents the operator from reaching the danger zone and is fixed to the machine so it cannot be removed without tools?
- Presence-sensing device
- Fixed guard (Correct answer)
- Two-hand control
- Awareness barrier
Correct answer: Fixed guard
A fixed guard is a permanent part of the machine and is held in place by fasteners that require tools to remove. It is the preferred safeguard when access to the point of operation is not needed.
Question 5: Under the lockout/tagout standard, when is a tagout-only system acceptable instead of lockout?
- Whenever it is faster to apply
- When the energy-isolating device is not capable of being locked out, and the tag gives equivalent protection (Correct answer)
- When only one employee is working on the machine
- Never; tags are not allowed
Correct answer: When the energy-isolating device is not capable of being locked out, and the tag gives equivalent protection
Tagout may be used if the device cannot be locked. The employer must then show that the tagout program gives full employee protection equivalent to lockout, with additional safety measures where needed.
Question 6: How often must an employer perform a periodic inspection of each energy control procedure?
- At least once every year (Correct answer)
- At least once every five years
- Only after an injury
- Every month
Correct answer: At least once every year
Employers must inspect each energy control procedure at least annually to ensure the procedure and requirements are being followed and to correct any deviations.
