OSHA 10-Hour Construction ReviewFocus Four HazardsMedium
A worker is performing maintenance on a piece of heavy machinery with multiple energy sources (electrical, hydraulic, pneumatic). Before beginning work, what is the MOST critical action the worker must take to prevent accidental startup or release of stored energy?
- APlace a 'Do Not Operate' tag on the machine.
- BInform co-workers that maintenance is being performed.
- CDisconnect all power sources and apply locks according to lockout/tagout procedures.
- DTest the machine's controls to ensure they are off.
Show answer & explanationAnswer & explanation
Correct answer: C. Disconnect all power sources and apply locks according to lockout/tagout procedures.
The most critical action is to apply a lockout/tagout (LOTO) procedure, which involves physically disconnecting and locking out all energy sources. Tags alone are warnings and testing controls only confirms current status; LOTO prevents accidental re-energization.
Why the other options are wrong
- A. Placing a 'Do Not Operate' tag is part of LOTO but is only a warning and not sufficient by itself to prevent accidental startup.
- B. Informing co-workers is an important communication step but does not physically prevent the machine from being energized.
- D. Testing controls ensures the machine is currently off but does not prevent someone from turning it back on while maintenance is in progress.
Lockout/Tagout (LOTO)
A safety procedure used to ensure that dangerous machines are properly shut off and not able to be started up again prior to the completion of maintenance or servicing work.
- Protects workers from unexpected startup or release of stored energy.
- Involves physically locking out energy-isolating devices.
- Requires specific procedures for different energy types.
Memory trick: Lock it, Tag it, Test it, or you'll regret it!