Safety
What the safety questions actually test
Most safety items on the millwright exam are about the sequence and verification of a control, not simply naming the hazard. The controlling standard in industrial settings is lockout/tagout (29 CFR 1910.147): notify affected employees, identify all energy sources - electrical, hydraulic, pneumatic, thermal, chemical, gravity, and stored energy in springs, capacitors, or accumulators - isolate, apply your own lock and tag, release or block stored energy, then verify the zero-energy state by attempting a normal start and testing with a meter.
Group lockout requires each worker's personal lock on the group hasp. Permit-required confined space entry (1910.146) requires atmospheric testing in a fixed order: oxygen first, then flammables, then toxics. Fall protection triggers at 6 ft in construction and 4 ft in general industry. Hot work permits, HazCom/SDS access, machine guarding, hand and power tool rules, housekeeping, and near-miss reporting complete the picture.
Traps
- Tagout alone is acceptable only when locking is demonstrably impossible and equivalent protection is provided.
- A lock without a start attempt is not lockout.
- An accumulator or a raised component still holds energy after the pump or power stops.
- Both oxygen-deficient and oxygen-enriched atmospheres are hazardous; 19.5–23.5% O2 is the acceptable band.
- Ladder and scaffold rules differ between construction and general industry.
Rule of thumb
The step people skip is verification: after isolation, press the start button and confirm nothing moves, then test for voltage. A written procedure outranks habit every time.