Machinery Safety Information

OSHA Safety Regulations for Industrial Machines and Equipment

ANSI Standards for Interlocked Guards

Interlocked Guards Overview

With the release of ANSI 11.19 (2010) - Performance Criteria for Safeguarding, it consolidated all of the design, installation, operation and maintenance of Fixed Guards into a single American National Standards Institude (ANSI) standard.

In the 2010 release of ANSI 11.19 there were two fundamental changes:
  • ANSI B11.19 (2010) now applies to ALL machines and equipment.
  • There is no longer any difference between the guarding standards for:
  • Point of Operation
  • Mechanical Transmission Apparatus

  • This significantly simplied the process of determining whether a guard met the current ANSI standads, as there is now a single unified standard for all safeguarding.

    For more on the ANSI B11.19 (2010) standards release, see ANSI Standards for Machine Guarding

    An example of an interlocked guard door


    Guard: A barrier that prevents exposure to a hazard.
  • Fixed
  • Adjustable
  • Interlocked
  • Perimeter

  • Performance Requirements

    Within the ANSI B11.19 (2010) Performance Criteria for Safeguarding, there are a number of important requirements. Note that these requirements apply to both Fixed and Interlocked Guards:

    7.1.1 Material used in the construction of guards shall be of such design and strength as to protect individuals from identified hazards.

    7.1.4 The design and construction of the guard shall ensure that individuals cannot reach the hazard by reaching over, under, around, or through the guard.

    7.2.1 Location of the guard with respect to the hazard shall ensure that individuals cannot reach the hazard by reaching over, under, around, or through the guard.

    7.1.5 Guards shall be designed and constructed so as to ensure ease of use.

    7.1.6 The guard shall be designed and constructed to provide visibility of the hazard zone appropriate to the particular operation.

    There are, however, many additional requirements that apply to Interlocked Guards. These include:

    7.2.4 The interlocked guard(s) shall be prevented from opening until the hazard has ceased, or shall be located so that an individual cannot reach the hazard before cessation of the hazard when the interlocked guard is opened.

    7.1.9 Interlock devices used in conjunction with guards shall be specifically designed and constructed for use in safeguarding applications.

    For ANSI B11.19 standards on fixed guarding, see: ANSI Standard for Fixed Guards

    For ANSI B11.19 standards on light curtains, see: ANSI Standard for Light Curtains

    For training on OSHA and ANSI methods of machinery and equipment guarding, see: OSHA and ANSI Training

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