OSHA’s Control of Hazardous Energy (Lockout/Tagout) general industry standard covers the servicing and maintenance of machines and equipment in which the unexpected energization or startup of machines or equipment, or release of stored energy, could cause injury to employees. Employees servicing or maintaining machines or equipment may be exposed to serious physical harm or death if hazardous energy is not properly controlled. The Lockout/Tagout (LO/TO) standard establishes minimum performance requirements for the control of hazardous energy sources such as electrical, mechanical, hydraulic, pneumatic, chemical, and thermal.
29 CFR 1910.147(a)(1)(ii)(A-E) of the general industry standard identifies the following areas the standard does not cover:
- Employment covered by Construction (1926), Agriculture (1928), Longshoring (1918), Marine Terminals (1917), or Shipyards (1915)
- Installations under the exclusive control of electric utilities for the purpose of power generation, transmission and distribution, including related equipment for communication or metering
- Exposure to electrical hazards from work on, near, or with conductors or equipment in electric-utilization installations, which is covered by 29 CFR 1910 Subpart S
- Oil and gas well drilling and servicing
To better understand when the LO/TO standard applies, OSHA has identified two key workplace activities. The first is normal production. This is defined as any utilization of a machine or piece of equipment to perform its intended purpose. The second is servicing and/or maintenance. This is defined as any action that is necessary to prepare or maintain a machine or piece of equipment for normal production.
As a general principle, the LO/TO standard does not apply to normal production activities unless the employee is required to remove or bypass machine guarding required by 29 CFR Part 1910 Subpart O, Machinery and Machine Guarding, or place any part of their body in an area where unexpected startup of the machine or equipment may cause injury.
If any of the following exceptions or exemptions are applicable to the servicing/maintenance activity being performed, then the LO/TO standard does not apply:
- Complying with the minor servicing exception (29 CFR 1910.147(a)(2)(ii)(B))
- Utilizing the cord and plug connected equipment or hot tap exemptions (29 CFR 1910.147(2)(iii)(A) and (B) respectively)
- Effectively guarding the machine/equipment in compliance with 29 CFR Part 1910 Subpart O
If you’re unsure about any activity that may or may not fall under the scope of this standard, always play it safe and perform the lockout.
Commonly Asked Questions
Q. What specific criteria must be met for the minor servicing exception to apply?
A: Minor tool changes and adjustments, and other minor servicing activities that take place during normal production operations, are not covered by the standard if they are routine, repetitive, and integral to the use of the equipment for production, provided that the work is performed using alternative measures (remote oilers, specially designed servicing tools, etc.) that provide effective protection.
Q. Do I have to lock out/tag out a machine that only requires the unit to be unplugged?
A: No. The standard does not apply in situations where work on cord- and plug-connected electric equipment is under the exclusive control of the employee performing the servicing or maintenance.
Q. Are there any other standards related to lockout/tagout?
A: Yes. OSHA has used 29 CFR 1910.212, General Requirements for All Machines, and 29 CFR 1910.219, Mechanical Power Transmission Apparatus, to cite businesses for a lack of compliance. In addition, 29 CFR 1910.333, Selection and Use of Work Practices, sets forth requirements to help protect employees working on electric circuits and equipment. This section requires workers to use safe work practices, including lockout/tagout procedures. These areas also allow OSHA to issue a double citation for noncompliance.
29 CFR 1910.147, 1910.219, and 1910.333.
ANSI/ASSP Z244.1-2016, Control of Hazardous Energy Lockout/Tagout and Alternative Methods, 2016
OSHA LO/TO eTool, Lockout/Tagout Interactive Training Program, March 2008