Also considered is unexpected startup due to release of stored energy from the machines or equipment. Lockout means the placement of a lock on an energy-isolating device of a machine or on equipment in order to prevent the operation of the machine or equipment until the lock is removed.
Energy isolating devices can include circuit breakers, switches, valves, and blocks.
Tagout means the placement of a tag which can be securely fastened to an energy-isolating device to indicate that the machinery or equipment may not be operated until the tagout device is removed. Also recorded will be the name of the employee who is responsible for the lockout or tagout, the expected time when repairs will be completed, and the actual time when the lockout or tagout were removed. The location and type of isolating devices will be determined before beginning work on any equipment which has energy supplied to it. Energy can include mechanical, hydraulic, pneumatic, chemical, thermal, and stored energy. More than one energy source may be available to a piece of equipment.