Research Publications-11, Lockout/Tagout

  • Bennett, Donald G.;
  • Forsen, Erik


Lockout/tagout (also called lockout/blockout) means that any energy source, be it electrical, hydraulic, mechanical or any other source that may cause unexpected movement, must be disengaged or blocked, and electrical sources must be de-energized and locked in the off position. In a U.S. Bureau of Labor Statistics survey on injuries related to servicing equipment, 80 percent of workers surveyed failed to turn off the equipment before performing the service work. There is a difference between turning off a machine and actually disengaging a piece of equipment. When turning off a control switch, you are opening a circuit; however, there is still electrical energy at the switch, and a short in the switch or someone turning on the machine may start it running again.
Failure to lock out and block out machinery before working on it is a major cause of injury and death in California and the United States. Workers can be electrocuted or lose fingers, hands, arms, or suffer severe crushing injuries because machinery is inadvertently turned on while being serviced or maintained. These injuries can be prevented by establishing an effective lockout program. An effective lockout/tagout program should include the following:

  • An inspection of equipment by a trained individual who is thoroughly familiar with the equipment operation and associated hazards
  • Identification and labeling of lockout devices
  • Purchase of locks, tags, and blocks
  • A standard written operating procedure that is followed by all employees
Laws and Regulations

Title 8, 3203, CCR requires every employer to initiate and maintain an accident prevention program.
Article 13, Title 8 CCR 3441 - Operation of Agricultural Equipment states that every employer shall instruct every employee in the safe operation and servicing of all equipment in which the employee will be involved.
Model programs

CAL/OSHA Components Of A Good Lockout Program- Illustrates general conditions that require locking out and blocking out machinery, along with methods of locking out equipment (in English and Spanish).

FELS - Lockout/Tagout. Program to train employees (in English and Spanish).

National Safety Council (NSC) - Lockout/Tagout booklet. Product #12812-0000.

Machine Safeguarding (NSC) - Alerts workers to machine hazards and safe operation of machinery. Product #15227-0000. Available in English or Spanish.

Lockout/Tagout (NSC) - Helps employees control hazardous energy sources during service and maintenance operations (booklet). Product #15242-0000.

Electrical Equipment Hazards (NSC) - (video) Product #19080- 2222.

OSHA - Lockout/Tagout - Department of Labor. This video covers OSHA regulations for the control of hazardous energy sources while maintenance and service duties are being performed.

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