The hazard
Machines can start up without warning, and stored energy can be released even after the power is off. Lockout tagout keeps a machine from moving or releasing energy while someone is working on it. It only works when everyone follows the same steps, every time.
The action
An authorized employee is the person who locks out or tags out a machine to service or maintain it. An affected employee runs that machine or works in the area where the servicing is being done. An affected employee becomes an authorized employee when their duties include that servicing or maintenance. (29 CFR 1910.147(b))
ASK THE CREW
Which machines in our area have more than one energy source, and where are their disconnects and valves?
From the talk: Lockout/tagout (LOTO). Read it in full, free, with the questions and the sign-in sheet.