"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.

LOTO is addressed in specific standards for the general industry, marine terminals, longshoring, and the construction industry.

Standards

This section 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), and national consensus standards related to LOTO.

Note: Twenty-five states, Puerto Rico and the Virgin Islands have OSHA-approved State Plans and have adopted their own standards and enforcement policies. For the most part, these States adopt standards that are identical to Federal OSHA. However, some States have adopted different standards applicable to this topic or may have different enforcement policies.

OSHA

General Industry (29 CFR 1910)

• 1910 Subpart J, General environmental controls
  • 1910.147, The control of hazardous energy (lockout/tagout)
    • Appendix A, Typical minimal lockout procedures
      
    
    
• 1910 Subpart R, Special industries
  • 1910.261, Pulp, paper, and paperboard mills [related topic page]
  • 1910.269, Electric power generation, transmission, and distribution [related topic page]
    • Appendix A, Flow charts
      
    
    
• 1910 Subpart S, Electrical
  • 1910.306, Specific purpose equipment and installations
  • 1910.333, Selection and use of work practices

Marine Terminals (29 CFR 1917)

• 1917 Subpart C, Cargo handling gear and equipment
  • 1917.48, Conveyors

Longshoring (29 CFR 1918)

• 1918 Subpart G, Cargo handling gear and equipment other than ship's gear
  • 1918.64, Powered conveyors

Construction Industry (29 CFR 1926)

• 1926 Subpart K, Electrical
  • 1926.417, Lockout and tagging of circuits
    
  
  
• 1926 Subpart Q, Concrete and masonry construction [related topic page]
  • 1926.702, Requirements for equipment and tools

Preambles to Final Rules

• Control of Hazardous Energy Sources (Lockout/Tagout) (1989)
  


• Search all available preambles to final rules.

Directives

• The Control of Hazardous Energy – Enforcement Policy and Inspection Procedures. OSHA Directive CPL 02-00-147, (2008, February 11). Cancels OSHA Instruction, STD 01-05-019 [STD 1-7.3], 29 CFR 1910.147, The Control of Hazardous Energy (Lockout/Tagout) -- Inspection Procedures and Interpretive Guidance, September 11, 1990 ; and its interpretations.
  


• Electrical Safety-Related Work Practices -- Inspection Procedures and Interpretation Guidelines. STD 01-16-007 [STD 1-16.7], (1991, July 1).
  


• Enforcement of the Electric Power Generation, Transmission, and Distribution Standard. CPL 02-01-038 [CPL 02-1.38], (2003, June 18).
  


• Search all available directives.

Standard Interpretations

• Recognition of ANSI/ASSE Z244.1-2003 "Control of Hazardous Energy - Lockout/Tagout and Alternative Methods" consensus standard. (2004, November 10).
  


• Printing Industry: Lock Out/Tag Out and the essential elements of the inch-safe-service technique. (2004, April 7).
  


• Clarification of "authorized" and "affected" employees and proper energy control procedures. (2004, February 10).
  


• Response to Exelon Generation's concerns regarding draft Instruction CPL 2-1.18A, "Enforcement of the Electric Power Generation, Transmission and Distribution Standard". (2003, June 13).
  


• Response to Edison Electric Institute's concerns regarding draft Instruction CPL 2-1.18A, "Enforcement of the Electric Power Generation, Transmission and Distribution Standard". (2003, June 13).
  


• Acceptability of modifying a standard on/off switch to provide lockout capability to a machine. (2003, May 13).
  


• Color is not the only prescribed factor for the standardization of LOTO devices. (2002, August 30).
  


• Use of verification tags for lockout. (2002, July 8).
  


• Authorized employees must have the opportunity to verify energy isolation in group lockout/tagout. (2002, January 29).
  


• Use of Electro Sensitive Protection Equipment as point of operation guarding devices. (2001, June 5).
  


• Clarification of system operator exclusive control provisions. (2000, November 21).
  


• Applicability of OSHA's LOTO standards; isolation and verification procedures. (2000, November 16).
  


• Search all available standard interpretations.

National Consensus

Note: These are NOT OSHA regulations. However, they do provide guidance from their originating organizations related to worker protection.

American National Standards Institute (ANSI)

• Z244.1-2003, Control of Hazardous Energy - Lockout/Tagout and Alternative Methods. Note: Compliance with the requirements of this consensus standard does not ensure compliance with the OSHA Lockout/Tagout Standard. For additional information, see Recognition of ANSI/ASSE Z244.1-2003 "Control of Hazardous Energy -- Lockout/Tagout and Alternative Methods" consensus standard.
  • Z244 Committee Information. American Society of Safety Engineers (ASSE).

Lockout/Tagout Concepts

"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. This requires that a designated individual turns off and disconnects the machinery or equipment from its energy source(s) before performing service or maintenance and that the authorized employee(s) either lock or tag the energy-isolating device(s) to prevent the release of hazardous energy and take steps to verify that the energy has been isolated effectively. The following references provide information about the LOTO process.

• Lockout/Tagout. National Ag Safety Database (NASD) Research Publications-11. Also available as a 49 KB PDF, 2 pages.
  


• Lockout/Tagout [212 KB PDF^*, 2 pages]. OSHA Fact Sheet, (2002). A Spanish version [49 KB PDF^*, 1 page] is also available.
  


• Preventing Worker Deaths from Uncontrolled Release of Electrical, Mechanical, and Other Types of Hazardous Energy. US Department of Health and Human Services (DHHS), National Institute for Occupational Safety and Health (NIOSH) Publication No. 99-110, (1999, August).
  


• Guidelines for Controlling Hazardous Energy During Maintenance and Servicing [Lockout/Tagout]. US Department of Health and Human Services (DHHS), National Institute for Occupational Safety and Health (NIOSH) Publication No. 83-125, (1983, September).

Lockout/Tagout Program

Example elements of a lockout/tagout (LOTO) program are described in the OSHA standard 29 CFR 1910.147, along with these additional references.

• 29 CFR 1910.147 Appendix A, Typical minimal lockout procedures. OSHA Standard. Provides assistance to employers in developing their procedures so they meet the requirements of 29 CFR 1910.147.
  


• Guidelines for Controlling Hazardous Energy During Maintenance and Servicing [Lockout/Tagout]. US Department of Health and Human Services (DHHS), National Institute for Occupational Safety and Health (NIOSH) Publication 83-125, (1983, September).
  


• Lockout/Tagout Interactive Training Program. OSHA eTool. Includes selected references for training and interactive case studies.
  • Case Studies
    
  
  
• For additional information, see OSHA's Safety and Health Programs Safety and Health Topics Page.

Additional Information

Related Safety and Health Topics Pages

• Electrical

Training

• Small Business Handbook. OSHA Publication 2209-02R, (2005). Also available as a 260 KB PDF, 56 pages.
  • Lockout/Tagout Procedures
  • Electrical
    
  
  
• Lockout/Tagout. National Ag Safety Database (NASD). Provides an index to several training videos available through NASD.

Other Resources

• Z244 Committee Information. American Society of Safety Engineers (ASSE).
  


• Accident Investigation Search. OSHA. Enables the user to search the text of Accident Investigation Summaries (OSHA-170 form) for words that may be contained in the text of the abstract or accident description.
  

Accessibility Assistance: Contact the OSHA Directorate of Technical Support and Emergency Management at (202) 693-2300 for assistance accessing PDF materials.

^*These files are provided for downloading.