Answer Library / Lockout/Tagout OSHA letter · 2021-05-21

Can a supervisor's lock cover the whole crew in a group lockout/tagout?

Quick answer

No. In group lockout, each authorized employee must personally attach their own lock to the group lockout device or lockbox before starting work and remove it when they finish — working under only a supervisor's lock does not comply (29 CFR 1910.147(f)(3)). A satellite lockbox arrangement where every crew member applies a personal lock does comply.

OSHA was asked to evaluate two group lockout scenarios involving three authorized employees replacing a pump. In Scenario 1, plant operations employees deenergized and locked out each energy source and placed the lockout keys in a group lockbox in the control room. A supervisor verified the zero energy state and applied a personal lock to the lockbox, and the three authorized employees then performed the pump replacement under the supervisor's lock without applying their own personal locks. A written log documented all employees and their clearance before the supervisor removed the lock.

OSHA said Scenario 1 does not comply with 29 CFR 1910.147(f)(3). The regulation 'requires each authorized employee to affix a personal lockout device to the group lockout device, group lockbox, or comparable mechanism when he or she begins work and to remove those devices when he or she stops working on the machine or the equipment being serviced or maintained.' A log book and a supervisor's lock are not a substitute for each worker's personal lock.

In Scenario 2, operations again deenergized and locked out all energy sources and placed the key in a control room lockbox. The supervisor locked that lockbox with a personal lock, then placed their key in a satellite lockbox at the pump site. Each crew member verified the zero energy state and applied their own personal lock to the satellite lockbox before beginning work, and removed it upon completion — meaning the supervisor could not retrieve the key while any crew member's lock remained. OSHA confirmed that Scenario 2 meets the requirements of 29 CFR 1910.147(f)(3).

29 CFR 1910.147(f)(3)
Source: OSHA Standard Interpretation letter, 2021-05-21 — read the official letter on osha.gov →
Interpretation letters explain how OSHA applies its rules to specific situations. Always verify current requirements — regulations and enforcement policies change.

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