MACHINE SAFETY: How to Comply with Machine Guarding Standards

Date First Published on SafetySmart Compliance: January 3rd, 2012
Topics: Machine Guarding |


OSHA machine guarding requirements for General Industry are set out in the Machinery and Machine Guarding subpart of the General Industry Standard (29 CFR 1910, Subpart O). Subpart O includes 2 basic kinds of machine guarding requirements:

General machine guarding requirements that apply to all machines (1910.212); and

Machine-specific requirements for particular kinds of machines, including:

  • Woodworking Machinery; 1910.213;
  • Abrasive Wheel Machinery, 1910.215;
  • Mills & Calendars in the Rubber & Plastics Industry, 1910.216;
  • Mechanical Power Presses, 1910.217;
  • Forging Machines; 1910.218; and
  • Mechanical Power-Transmission Apparatus, 1910.219.

This article looks at the Subpart from 30,000 feet and focuses on general requirements and approach. For detailed information about a specific item, click on the link and you’ll be taken to our comprehensive OVERVIEW.

What Machine Guarding Involves

Machine guarding means using physical, mechanical and other devices, such as electronic devices that automatically shut off the machine when somebody puts his hand into a danger zone. Employers must use 1 or more machine guarding methods to protect the operator and other employees in the machine area.

Guards must be physically secured by affixing guard to the machine. If that’s impossible to attach the guard to the machine, the guard must be secured elsewhere.

Machines designed for a fixed location must  also be securely anchored to prevent walking or moving.

When Machine Guarding Is Required

OSHA mandates that machines guards be used to protect workers in 3 areas:

  • The point of operation, i.e., the part of the machine where the cutting, shaping, boring, forming or other operation is done on the material;
  • All parts of the machine that move, such as:
    1. Flywheels, pulleys, belts, couplings, chains, cranks, gears, etc.
    2. Feed mechanisms and auxiliary parts of the machine
      • In-running nip points

      Basic Types of Machine Guards

      Machine guards fall under 5 general categories:

      1. Guards – fixed, interlocked, adjustable, and self-adjusting
      2. Devices – presence sensing, pullback, restraint, safety controls (tripwire cable, two-hand control, etc.), and gates
      3. Location/distance
      4. Feeding and ejection methods – automatic and/or semi-automatic feed and ejection, and robots
      5. Miscellaneous aids – awareness barriers, protective shields, and hand-feeding tools

      General Standards for Guards and Guarding Equipment

      Guards must adhere to the following basic principles:

      • They must prevent the worker’s body or clothing from coming in contact with hazardous moving parts.
      • They must be firmly secured to the machine and not easily removed.
      • They must ensure that no objects can fall into moving parts.
      • They may not create any new hazards such as shear points, jagged edges or unfinished surfaces.
      • They may not create any interference and prevent worker from performing the job quickly and comfortably.
      • They must allow for safe lubrication of the machine without removing the safeguards, if possible.

      Requirements for Point of Operation Guards

      The point of operation must be guarded if it poses a danger. Examples of machines with dangerous points of operation: guillotine cutters, shears, power presses, milling machines, power saws, jointers and portable power tools.

      Point of operation guards must meet the appropriate OSHA standard for the kind of machine and hazard involved. Guards may be supplemented with—though not replaced by—special handtools that allow operators to place and remove materials from the machine without sticking their hands in the danger zone.

      Revolving drums, barrels and containers must be guarded by an enclosure that’s interlocked with the drive mechanism, so that the barrel, drum or container can’t revolve unless the guard enclosure is in place.


      One common mistake many employers make is to purchase machinery that’s unguarded and simply assume they don’t need to do anything further because they machine wouldn’t have been sold to them if it didn’t meet governmental regulations. This unfortunate mistake is based on flawed assumptions about legal requirements and has been the cause of many injuries and fatalities as well as fines from regulatory agencies.