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Machine Guarding

Moving machine parts have the potential to cause severe workplace injuries, such as crushed fingers or hands, amputations, burns, or blindness. Safeguards are essential for protecting workers from these preventable injuries. Any machine part, function, or process that may cause injury must be safeguarded. When the operation of a machine or accidental contact injure the operator or others in the vicinity, the hazards must be eliminated or controlled. This page contains general information on the various hazards of mechanical motion and techniques for protecting workers.

Machine guarding hazards are addressed in specific standards for the general industry, marine terminals, longshoring, and the construction and agriculture industries.


This section highlights OSHA standards, Federal Registers (rules, proposed rules, and notices), directives (instructions for compliance officers), standard interpretations (official letters of interpretation of the standards), and national consensus standards related to machine guarding.


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.

General Industry (29 CFR 1910)

  • 1910 Subpart O, Machinery and machine guarding. Includes definitions, general requirements, and different kinds of machinery requirements.
    • 1910.211, Definitions
    • 1910.212, General requirements for all machines
    • 1910.213, Woodworking machinery requirements
    • 1910.214, Cooperage machinery [Reserved]
    • 1910.215, Abrasive wheel machinery
    • 1910.216, Mills and calendars in the rubber and plastics industries
    • 1910.217, Mechanical power presses. Includes general requirements in addition to specific requirements for construction, safeguarding, dies, inspection, maintenance, modification, operation, injury reporting, and presence sensing device initiation (PSDI).
      • Appendix A, Mandatory requirements for certification/validation of safety systems for presence sensing device initiation of mechanical power presses
      • Appendix B, Nonmandatory guidelines for certification/validation of safety systems for presence sensing device initiation of mechanical power presses
      • Appendix C, Mandatory requirements for OSHA recognition of third-party validation organizations for the PSDI standard
      • Appendix D, Nonmandatory supplementary information
    • 1910.218, Forging machines
    • 1910.219, Mechanical power-transmission apparatus
  • 1910 Subpart R, Special industries

Marine Terminals (29 CFR 1917)

Longshoring (29 CFR 1918)

  • 1918 Subpart I, General working conditions
    • 1918.96, Maintenance and repair work in the vicinity of longshoring operations. Paragraph (e) contains general requirements for machine guarding (see also 29 CFR 1918.2, definition of "danger zone").

Construction Industry (29 CFR 1926)

  • 1926 Subpart I, Tools - Hand and power. Includes general machine guarding requirements and specific guarding requirements for different types of tools.

Agriculture Industry (29 CFR 1928)

  • 1928 Subpart D, Safety for agricultural equipment
    • 1928.57, Guarding of farm field equipment, farmstead equipment, and cotton gins

Federal Registers

  • Mechanical Power -- Transmission Apparatus; Mechanical Power Presses; Telecommunications; Hydrogen. Final Rules 69:31880-31882, (2004, June 8). Corrects errors in four OSHA standards:
    1. The first correction deletes two references to a non existing table in the Mechanical Power-Transmission Apparatus Standard.
    2. The second is a correction of typographical errors in the Mechanical Power Presses Standard.
    3. The third correction is to a cross-reference in the Telecommunications Standard.
    4. The fourth correction is to a reference to a table contained in the Hazardous Materials Standard for Hydrogen.

  • Notice of Availability of the Regulatory Flexibility Act Review of Presence Sensing Device Initiation for Mechanical Power Presses. Proposed Rules 69:31927-31929, (2004, June 8). OSHA has conducted a review of the Presence Sensing Device Initiation (PSDI) requirements of the Mechanical Power Presses Standard pursuant to section 610 of the Regulatory Flexibility Act, and section 5 of Executive Order 12866 on Regulatory Planning and Review. Based on this review and public comments, OSHA has decided to update its mechanical power press standard to ANSI B.11.1-2001

  • Mechanical Power Presses. Final Rules 53:8322-65, (1988, March 14). Amendment of the standard for mechanical power presses, 29 CFR 1910.217, to allow (but not require) presence sensing device initiation (PSDI) on certain types of power presses.

  • Search all available Federal Registers.


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)

  • ANSI B11 Subcommittees. The ANSI B11 committee is responsible for developing machine tool safety standards. This document provides brief descriptions of the subcommittees and the hazards they are addressing.
    • B11.1-2001, Safety Requirements for Mechanical Power Presses
    • B11.2-1995 (R05), Hydraulic Power Presses - Safety Requirements for Construction, Care, and Use
    • B11.3-2002, Safety Requirements for Power Press Brakes
    • B11.4-2003, Safety Requirements for Shears
    • B11.5-1988 (R05), Ironworkers - Safety Requirements for Construction, Care, and Use
    • B11.6-2001, Safety Requirements for Manual Turning Machines with or without Automatic Control
    • B11.7-1995 (R05), Cold Headers & Cold Formers - Safety Requirements for Construction, Care, and Use
    • B11.8-2001, Safety Requirements for Manual Milling, Drilling, & Boring Machines with or without Automatic Control
    • B11.9-1975 (R05), Safety Requirements for the Construction, Care, and Use of Grinding Machines
    • B11.10-2003, Safety Requirements for Metal Sawing Machines
    • B11.11-2001, Safety Requirements for Gear and Spline Cutting Machines
    • B11.12-2005, Safety Requirements for Roll Forming & Roll Bending Machines
    • B11.13-1992 (R98), Single and Multiple-Spindle Automatic Bar, and Chucking Machines - Safety Requirements for Construction, Care, and Use
    • B11.14-1996, Coil Slitting Machines - Safety Requirements for Construction, Care, and Use
    • B11.15-2001, Safety Requirements for Pipe, Tube and Shape Bending Machines
    • B11.16-2003 (MPIF #47), Safety Requirements for Powder/Metal Compacting Presses
    • B11.17-2004, Safety Requirements for Horizontal Hydraulic Extrusion Presses
    • B11.18-1997, Safety Requirements for Machines and Machinery Systems for Processing or Slitting or Non-Coiled Metal Strip, Sheet or Plate
    • B11.19-2003, Performance Criteria for Safeguarding
    • B11.20-2004, Safety Requirements for Integrated Manufacturing Systems
    • B11.21-1997, Safety Requirements for Machine Tools Using Lasers For Processing Materials
    • B11.22-2002, Safety Requirements for Turning Centers and Automatic Numerically Controlled Turning Machines
    • B11.23-2002, Safety Requirements for Machining Centers and Automatic Numerically Controlled Milling, Drilling and Boring Machines
    • B11.24-2002, Safety Requirements for Transfer Machines
    • B11.TR 1-2004, Ergonomic Guidelines for the Design, Installation
      And Use of Machine Tools
    • B11.TR 2-1997, Mist Control Considerations for the Design, Installation
      And Use of Machine Tools Using Metalworking Fluids
    • B11.TR 3-2000, Risk Assessment and Risk Reduction- A Guideline to Estimate, Evaluate and Reduce Risks Associated with Machine Tools
    • B11.TR 4-2004, Selection of Programmable Electronic Systems (PES/PLC) for Machine Tools
    • B11.TR5-200X, Sound Level Measurement Guidelines (not an approved document; in development)
    • B11.TR6-200X, Control Reliable Circuits and Servo Drive Technology

Hazard Recognition

The following references aid in recognizing hazards from ineffective machine guarding.

Possible Solutions

The following references provide possible solutions for machine guarding hazards.

Additional Information

Related Safety and Health Topics Pages


Other Resources

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