Workers performing service or maintenance on machinery and equipment are exposed to injuries from the unexpected energization, startup of the machinery or equipment, or release of stored energy in the equipment.
OSHA's Lockout/Tagout (Control of Hazardous Energy) standard, which went into effect in January 1990, helps safeguard employees from the unexpected startup of machines or equipment or release of hazardous energy while they are performing servicing or maintenance. It identifies the practices and procedures necessary to shut down and lock out or tag out machines and equipment, requires that employees receive training in their role in the lockout/tagout program, and mandates that periodic inspections be conducted to maintain or enhance the energy control program.
This rule requires that, in general, before service or maintenance is performed on machines or equipment, the machines or equipment must be turned off and disconnected from the energy source, and the energy-isolating device must be either locked or tagged out.
Lockout is a more reliable means of deenergizing equipment than tagout and it should always be the preferred method used by employees. Except for limited situations, the use of lockout devices will provide a more secure and more effective means of protecting employees from the unexpected release of hazardous energy or startup of machines and equipment.
The Lockout/Tagout standard applies to general industry employment and covers the servicing and maintenance of machines and equipment in which the unexpected startup or the release of stored energy could cause injury to employees. Hazardous energy releases may occur during the installation, set up, adjusting, modifying, maintenance, servicing, or repairing of machines, equipment, processes, or systems.
It applies to any source of mechanical, hydraulic, pneumatic, chemical, thermal, or other energy, but does not cover electrical hazards. Subpart S of 29 CFR Part 1910 covers electrical hazards, and 29 CFR Part 1910.333 contains specific lockout/tagout provisions for electrical hazards.
Servicing and maintenance of equipment performed during normal production operations are not covered if:
§ The safeguarding provisions of OSHA's Machine Guarding and other applicable general industry standards are effective in preventing worker exposure to hazards created by the unexpected energization or startup of machines or equipment, or the release of energy.
§ Minor tool changes and adjustments, and other minor servicing activities that take place during normal production operations which are routine, repetitive, and integral to the use of that production equipment, as long as workers are effectively protected by alternative measures which provide effective machine safeguarding protection.
§ Construction, agriculture, and maritime workers.
§ Installations under the exclusive control of electric utilities for power generation, transmission, and distribution.
§ Exposure to electrical hazards from work on, near, or with conductors or equipment in electric utilization installations.
§ Oil and gas well drilling and servicing.
§ Work on cord and plug connected electrical equipment — if the equipment is unplugged from the energy source and the authorized employee has exclusive control of the plug.
§ Hot tap operations that involve transmission and distribution systems for gas, steam, water, or petroleum products on pressurized pipelines — if continuity of service is essential, shutdown of the system is impractical, documented procedures are followed, and employees are effectively protected by special equipment.