Safety Comic of the Day – “OSHA Machine Guarding Requirements”

Machine Guarding Safety

Crushed hands and arms, severed fingers and limbs, lacerations and abrasions – the list of possible machinery-related injuries is long and horrifying. Many hazards are created by moving machine parts. Safeguards are essential for protecting workers from preventable injuries.

The following standards have been established to ensure the safety of machine operators and other employees in the area:

For a printable sample employer self-inspection checklist for safeguards & other hazards, see Appendix G.or click below for a copy:

The purpose of machine guarding is to protect the machine operator and other employees in the work area from hazards created by ingoing nip points, rotating parts, flying chips and sparks. Some examples of this are barrier guards, light curtains, two-hand operating devices etc. [29 CFR 1910.212(a)(1)]

General Requirements: [29 CFR 1910.212(a)(2)]

  • Guards must not create potential hazards and must be attached to the machine where possible.
  • If guards cannot be attached to the machine, attach elsewhere.

The point of operation is the area on a machine where work is performed. [29 CFR 1910.212(a)(3)(i)]

Machines that expose an employee to injury must be guarded. The guarding device must:

  • If specific standards are not available, the machine construction should prevent the operator from having any part of his/her body in the danger zone during the operating cycle. [29 CFR 1910.212(a)(3)(ii)]
  • Special handtools used for placing and removing material from point of operation areas must allow easy handling of the material without the operator placing a hand in the danger zone. Such tools must not replace guards required by this section. [29 CFR 1910.212(a)(3)(iii)]

Additional Guarding

The following is a list of machines that usually require point of operation guarding:
[29 CFR 1910.212(a)(3)(iv)]

  • Guillotine cutters (a)
  • Shears (b)
  • Alligator shears (c)
  • Power presses (d)
  • Milling machines (e)
  • Power saws (f)
  • Jointers (g)
  • Portable power tools (h)
  • Forming rolls and calenders (i)

Barrels, Containers, and Drums Revolving barrels, containers, and drums must be guarded by an enclosure interlocked with the drive mechanism, so the barrel, gun, or container cannot revolve unless the guard enclosure is in place. [29 CFR 1910.212(a)(4)]

Exposure of Blades When the periphery of the blades of a fan is less than seven (7) feet above the floor or working level, the blades must be guarded. The guard must not have openings larger than one-half (½) inch. [29 CFR 1910.212(a)(5)]

Anchoring Fixed Machinery A machine designed for a fixed location must be securely anchored to prevent walking or moving. [29 CFR 1910.212(b)]

Eye and Face Protection Eye and face protection must be provided to each employee when exposed to eye or face hazards from flying particles. [29 CFR 1910.133(a)]

For more information, please refer to:

Lockout/Tagout The employer must establish an energy control program consisting of energy control procedures, employee training, and periodic inspections to ensure that before any employee performs any servicing or maintenance on a machine or equipment, the machine or equipment is isolated from the energy source and rendered inoperative. [29 CFR 1910.147(c)(1)]

For more information, refer to:

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.


  • National Emphasis Program on Amputations. CPL 03-00-003, (2006, October 27). Describes policies and procedures for implementing a National Emphasis Program (NEP) to identify and reduce or eliminate the workplace incidence of hazards which are causing or are likely to cause amputations.
  • 29 CFR 1910.217 Mechanical Power Presses, Clarifications. STD 01-12-021 [STD 1-12.21], (1978, October 30). Provides a guide to aid in the recognition of mechanical power presses’ point of operation hazards and uniform clarifications of definitions, guards, develop and methods of safeguarding.

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.

  • ANSI B11 Subcommittees. Provides brief descriptions of the subcommittees and the hazards they are addressing. The American National Standards Institute’s (ANSI) B11 committee is responsible for developing machine tool safety standards. Additional information about ANSI standards is available on their website.
  • Machine Safety. National Institute for Occupational Safety and Health (NIOSH) Workplace Safety & Health Topic. Links to several documents that discuss machinery safety for different types of agricultural equipment, and machine guarding in general.

Possible Solutions

The following references provide possible solutions for machine guarding hazards.

  • Preventing Scalping and Other Severe Injuries from Farm Machinery. US Department of Health and Human Services (DHHS), National Institute for Occupational Safety and Health (NIOSH) Publication No. 94-105, (1994, June). Describes five cases of persons who were scalped when their hair became entangled around the inadequately guarded rotating drivelines or shafts of farm machinery driven by power take-offs (PTOs).
  • Preventing Farm Machine Hazards [204 KB PDF, 3 pages]. The Ohio State University Extension Fact Sheet AEX-593-91. Discusses hazards associated with farm machinery and the importance of guarding.

Additional Information

Related Safety and Health Topics Pages


Other Resources

  • Association for Manufacturing Technology (AMT). Accredited Standards Developing Organization (SDO) for the ANSI B11 series of standards for machine tools.


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