All power sources—electrical, mechanical, pneumatic, hydraulic—must be shut off and locked/tagged out during machine maintenance. This includes power that is stored in a machine, such as compressed air in a cylinder, after the machine is turned off. To achieve this, you must have a written lockout/tagout plan that, for each machine, describes all power sources and the correct procedure for shutting down, testing, and re-energizing the equipment. A plan should describe how employees will be notified when a lockout/tagout is necessary, and shall require employees to always lock out or tag out equipment, using the appropriate procedures, before performing work on the equipment.

To develop your energy control program, inventory your equipment and identify all power sources. Identify the lockout devices that you will need for your particular machines. There are many commercially available devices for locking out electrical switches, circuit breakers, valves, compressed-air lines, hydraulic equipment, and other power sources. When feasible, affected employees must be given their own lock to use during lockout procedures. If tagout devices are used in place of lockout devices, the tagout program must be as effective as the lockout program. Train all affected employees about the company’s plan: the program will only work if employees understand how to implement the correct lockout/tagout procedures. OSHA’s standard, 1910.147, establishes specific requirements for lockout/tagout programs.