A worker is performing maintenance on a piece of heavy machinery with multiple energy sources. Before beginning work, the worker applies a lock and tag to the main power switch. However, the machine also has hydraulic and pneumatic systems. What critical step has the worker missed according to lockout/tagout procedures?
- AApplying locks and tags to all energy-isolating devices for every energy source.
- BTesting the machine to ensure all energy sources are de-energized.
- CNotifying all affected employees before applying the lock and tag.
- DEnsuring only one person is assigned to apply and remove the lock and tag.
Show answer & explanationAnswer & explanation
Correct answer: A. Applying locks and tags to all energy-isolating devices for every energy source.
OSHA's Lockout/Tagout standard (1910.147(d)(4)) requires that all energy-isolating devices related to the machine being serviced or maintained must be locked out and tagged out. This includes not only electrical but also hydraulic, pneumatic, mechanical, thermal, and gravitational energy sources. Missing any source leaves the potential for unexpected energization.
Why the other options are wrong
- B. This is also a correct and crucial step, but it must be done *after* all energy sources are locked out, not before they are identified and controlled.
- C. This is a correct step in the LOTO procedure, but it's not the critical step missed regarding *all* energy sources.
- D. This refers to individual worker responsibility in a group LOTO, but the core issue is controlling *all* energy types.
Lockout/Tagout (All Energy Sources)
Lockout/Tagout (LOTO) procedures require that all forms of hazardous energy associated with machinery (electrical, hydraulic, pneumatic, mechanical, etc.) are identified, isolated, locked, and tagged before maintenance or servicing begins to prevent accidental energization.
- LOTO is one of OSHA's 'Focus Four Hazards' (Electrocution).
- A 'lockout' physically prevents energy isolation devices from being operated.
- A 'tagout' is a warning placed on the device indicating it must not be operated.
Memory trick: Prepare, Shut Down, Isolate All, Lock/Tag, Verify, Release.