Control of Hazardous Energy (Lockout/Tagout)

"Lockout/Tagout (LOTO)" refers to specific practices and procedures to safeguard employees from the unexpected energization or startup of machinery and equipment, or the release of hazardous energy during service or maintenance activities.

Approximately 3 million workers service equipment and face the greatest risk of injury if lockout/tagout is not properly implemented. Compliance with the lockout/tagout standard (29 CFR 1910.147) prevents an estimated 120 fatalities and 50,000 injuries each year. Workers injured on the job from exposure to hazardous energy lose an average of 24 workdays for recuperation. In a study conducted by the United Auto Workers (UAW), 20% of the fatalities (83 of 414) that occurred among their members between 1973 and 1995 were attributed to inadequate hazardous energy control procedures specifically, lockout/tagout procedures.

Lockout is the placement of a lockout device on an energy isolation device (circuit breaker, slide gate, line valve, disconnect switch, etc.) to ensure that the energy isolating device and equipment being controlled cannot be operated until the lockout device is removed. A lockout device utilizes a positive means such as a lock (key or combination type) to hold an energy isolating device in a safe position and prevent the energization of a machine or equipment. The lockout device must be substantial enough to prevent removal without use of excessive force or unusual techniques.

Tagout is the placement of a tagout device (a tag or other prominent warning device and a means of attachment) on an energy isolation device to indicate that the energy isolating device and the equipment being controlled may not be operated until the tagout device is removed.

Standards

Lockout/tagout (LOTO) is addressed in specific standards for the general industry, marine terminals, longshoring, and the construction industry. This page highlights OSHA standards, preambles to final rules (background to final rules), directives (instructions for compliance officers), standard interpretations (official letters of interpretation of the standards), example citations, and national consensus standards related to LOTO.

OSHA

Section 5(a)(1) of the OSH Act, often referred to as the General Duty Clause, requires employers to "furnish to each of his employees employment and a place of employment which are free from recognized hazards that are causing or are likely to cause death or serious physical harm to his employees". Section 5(a)(2) requires employers to "comply with occupational safety and health standards promulgated under this Act".

Written Program

OSHA 29 CFR 1910.147 (c)(4) covers the minimal acceptable written program procedures. It must include:

1. A specific written statement of the intended use of the procedure.
2. Specific procedural steps are taken for shutting down, isolating, blocking and securing machines or equipment to control hazardous energy. This must be done for each piece of equipment, unless it is a duplicate.
3. Specific procedural steps for the placement, removal and transfer of lockout devices and the responsibility for them.
4. Specific requirements for testing the effectiveness of the lockout devices, tagout devices and other energy control measures.

Training

Training of employees will be done by an authorized employee [29 CFR 1910.147 (c)(7)(I)]. The affected employees shall be instructed in the purpose and use of the energy control procedure and all other employees whose work operations are or may be in an area where energy control procedures may be utilized. When tagouts are used, employees must be instructed in the limitations of these devices.

Employee retraining shall be provided for all authorized and affected employees whenever there is a change in their job assignments, a change in machines, equipment or processes that present a new hazard, or when there is a change in the energy control procedures. After January 2, 1990, whenever replacement or major modification of a machine or equipment is performed, and whenever new machines or equipment are installed, energy isolating devices for such machines or equipment shall be designed to accept a lockout device.

Removal of Lockout/Tagout Devices

Before lockout or tagout devices are removed, the authorized employee shall ensure that non-essential items are removed and machine components are operationally intact. The area should be checked to ensure all employees are safely positioned or removed and all affected employees notified that lockout/tagout devices have been removed. The lockout/tagout device must be removed by the person who applied the device. If the person who applied the device is not available, the device may be removed by another employee if the employer has established a specific procedure and training for this. When group lockout/tagout devices are used, a procedure equivalent to the personal lockout/tagout system should be followed. [(29 CFR 1910.147 (f)(3)]

Commonly Asked Questions