OSHA 1910.147(e)(3)
What it means on the job
OSHA 1910.147 requires each lock to be removed by the employee who applied it. Removal by anyone else is permitted only under a specific documented procedure that includes verifying the employee is not in the facility and informing them before they return to work. A master key kept for convenience defeats the single guarantee the standard provides — that your lock is the only thing that can start that machine while you are inside it.
Tested in 1 CraftIQ puzzle
- whats-wrongLockout/Tagout on a Process Pump
Related OTHER sections
OSHA 1910.147 / NFPA 70E 120.5
Removing an MCC bucket while the bus is energized exposes the worker to live 480V bus stabs and creates an arc flash hazard. OSHA 1910.147 and NFPA 70E require the MCC to be de-energized and locked out/tagged out before withdrawing any bucket unless the equipment is specifically designed for hot-swap operation.
OSHA 1910.147(c)(2)
OSHA 1910.147 requires an energy isolating device capable of being locked out to be LOCKED out. A tag alone is a warning, not a control — it stops nobody who does not read it. Proximity to the crew is not a substitute; the rule exists precisely because the person who re-energizes equipment usually does not know anyone is working on it.
OSHA 1910.147(d)(6)
OSHA 1910.147(d)(6) requires the authorized employee to VERIFY that isolation and de-energization have actually been accomplished before starting work — by testing for absence of voltage and attempting a normal start. A handle position is an indication, not a verification. Handles break, contacts weld, and the disconnect you opened is not always the one feeding the equipment.
OSHA 1910.212 / SMACNA Safety Manual
Pittsburgh lock seam machines have pinch points that can amputate fingers. Machine guards are required by OSHA and must never be bypassed or removed. SMACNA apprenticeship training specifically emphasizes: never defeat a machine guard.
OSHA 1910.252 / AWS Z49.1
Plasma cutting produces intense UV/IR radiation and bright arc flash that causes eye damage (arc eye) and skin burns. A welding screen or curtain must be deployed around the cutting area to protect the operator and nearby workers.
OSHA 1910.252(c) / ACGIH TLV Guidelines
OSHA 1910.252(c) requires adequate ventilation for all welding operations. In confined or enclosed spaces, mechanical ventilation must provide a minimum of 2,000 CFM per welder. Welding fumes contain hexavalent chromium, manganese, and other toxic metals that exceed OSHA PELs without proper exhaust ventilation.
CraftIQ explanations are original educational commentary written in trade language and verified against the cited standards. Always confirm requirements against the code edition adopted by your jurisdiction — this is training material, not a substitute for the code book or your AHJ.