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Machine Guarding

Safe At Work Ontario
  • Issued: October 31, 2014
  • Content last reviewed: October 2014

Disclaimer: This resource has been prepared to help the workplace parties understand some of their obligations under the Occupational Health and Safety Act (OHSA) and regulations. It is not legal advice. It is not intended to replace the OHSA or the regulations. For further information please see full disclaimer.


When machines are not properly guarded or locked out during maintenance, repair and other activities at industrial sector workplaces, workers can be exposed to a number of hazards. These hazards can result in serious injuries such as amputations of limbs or death.

Hazards can include:

  • Exposure to in-running nip hazards, i.e. getting caught up in machinery and moving parts if equipment is not properly guarded.
  • Exposure to hazardous motion, such as rotating machine parts, if equipment is not properly locked and blocked during maintenance and repair.

In 2012, the Workplace Safety and Insurance Board received the following claims from workers for 'lost-time injuries' (LTIs areinjuries which resulted in workers having to take time off work):

  • 1,976 workers were caught in or compressed by equipment.
  • 305 workers were rubbed or abraded by friction, pressure or jarred by vibration.
  • 367 workers had body parts amputated.

In 2013, 17 per cent or 2,737 of all orders issued by Ministry of Labour inspectors under the Regulations for Industrial Establishments were for machine guarding and lockout violations.

Duties and responsibilities

Employers, supervisors and workers have responsibilities under the Occupational Health and Safety Act (OHSA) and Regulations for Industrial Establishments.

Some of the responsibilities may include:


Providing appropriate information, instruction and supervision to protect workers such as training in lockout and guarding procedures (OHSA Section 25(2)(a)). Ensuring equipment is maintained in good condition by replacing and/or repairing damaged machine components (OHSA Section 25(1)(b)).

  • Ensuring an appropriate machine guard or other device exists to protect workers when:
    • A moving part may endanger workers (Industrial Regulation Section 24).
    • A machine has an in-running nip hazard (Industrial Regulation Section 25).
  • Ensuring appropriate lockout and blocking procedures by:
  • Cleaning, oiling, adjusting, repairing or having maintenance done on machines (Industrial Regulation Section 75).
  • Locking out control switches or other control mechanisms, or taking other effective precautions to prevent starting, when the starting of the machine could endanger a worker (Industrial Regulation Section 76).


  • Taking every reasonable precaution in the circumstances for the protection of workers
    (OHSA 27(2)(c)).
  • Ensuring workers comply with the OHSA and its regulations (OHSA 27(1)(a)).
  • Ensuring workers use any equipment, protective devices or clothing required by the employer
    (OHSA 27(1)(b)).
  • Advising workers of any potential or actual health and safety dangers (OHSA 27(2)(a)).


  • Following lockout and guarding procedures (OHSA 28(1)(a)).
  • Reporting machine hazards and other workplace hazards to their supervisor (OHSA 28(1)(c)).
  • Using or operating machinery in a safe manner (OHSA 28(2)(b)).
  • Using or wearing protective devices or clothing required by the employer (OHSA 28(1)(b)).

More information

Call toll-free

Call 1-877-202-0008 anytime to report workplace health and safety incidents or for general inquiries about health and safety at the workplace. Always call 911 in an emergency.

Disclaimer: This web resource has been prepared to assist the workplace parties in understanding some of their obligations under the Occupational Health and Safety Act (OHSA) and the regulations. It is not intended to replace the OHSA or the regulations and reference should always be made to the official version of the legislation.

It is the responsibility of the workplace parties to ensure compliance with the legislation. This web resource does not constitute legal advice. If you require assistance with respect to the interpretation of the legislation and its potential application in specific circumstances, please contact your legal counsel.

While this web resource will also be available to Ministry of Labour inspectors, they will apply and enforce the OHSA and its regulations based on the facts as they may find them in the workplace. This web resource does not affect their enforcement discretion in any way.