STSC Lockout/Tagout and Hazardous Energy Control

Question 1

Under OSHA construction standards, what is the FIRST step a worker must take before performing maintenance on powered equipment?

Accepted Answer

De-energize the equipment and apply a lockout device

Answer

OSHA's hazardous energy control requirements mandate that the equipment be fully de-energized and a lockout device applied before any maintenance or servicing begins. Notification and PPE are secondary steps that follow, not precede, isolation.

Question 2

A crew must replace a hydraulic hose on an excavator. After shutting off the engine, what additional step is REQUIRED before starting the repair?

Accepted Answer

Bleed residual hydraulic pressure and verify the zero-energy state

Answer

Stored hydraulic energy can cause sudden, violent movement even after the engine is off. OSHA requires that all stored energy — including hydraulic, pneumatic, spring, and gravitational — be released and verified at zero before work begins.

Question 3

When multiple authorized workers are simultaneously performing maintenance on the same piece of equipment, OSHA requires:

Accepted Answer

Each authorized worker to apply their own personal lock to the energy-isolating device or hasp

Answer

OSHA group lockout procedures require each authorized employee to apply their own personal lock. No worker's safety should depend on another person's lock — each individual must be able to verify their own protection.

Question 4

A tagout device may be used WITHOUT an accompanying lockout device ONLY when:

Accepted Answer

The energy-isolating device cannot physically accommodate a lock

Answer

Tags alone may substitute for locks only when the physical design of the energy-isolating device prevents a lock from being applied. Even then, OSHA requires additional equivalent means of protection, because a tag by itself provides no physical restraint.

Question 5

Which of the following is classified as a form of 'stored energy' that must be controlled during a lockout/tagout procedure?

Accepted Answer

Compressed air remaining in a pneumatic line

Answer

Stored energy includes mechanical (springs, gravity), electrical (capacitors), thermal (steam), chemical, and pneumatic (compressed air or gas) energy. Compressed air in a pneumatic line can release suddenly and cause unexpected equipment movement or injury.

(STSC) Safety Trained Supervisor Construction Practice Test

(STSC) Safety Trained Supervisor Construction Practice Test

STSC Lockout/Tagout and Hazardous Energy Control