Overview

From April 1, 2024 to March 31, 2025, the Ministry of Labour, Immigration, Training and Skills Development (MLITSD) conducted a health and safety campaign which focused on airborne hazard management and underground ventilation for diesel-powered equipment for mine and mining plant workers in Ontario.

The campaign began by focusing on education, training, outreach and awareness, in partnership with the Infrastructure Health and Safety Association (IHSA) and Workplace Safety North (WSN). The goal was to help workplace parties comply with the requirements for training under the Occupational Health and Safety Act (OHSA) and Regulation 854: Mines and Mining Plants prior to focused inspections.

To support and enforce compliance with the OHSA and its regulations, between June 1, 2024 and March 31, 2025, MLITSD inspectors carried out focused inspections in the workplace.

MLITSD inspectors:

  • conducted 134 field visits including 22 field visits with a support role activity (an activity in which another inspector or a professional services staff such as a hygienist, ergonomist or engineer accompanies an inspector on a field visit to provide professional support and expertise)
  • visited 92 workplaces
  • issued 339 orders and requirements, including 28 stop work orders

Background

The 2015 Mining Health, Safety, and Prevention Review, identified occupational disease (particularly those related to airborne hazards) as one of the five key issues that posed the greatest risk to worker health and safety.

Additionally, there were substantial new regulatory changes to Regulation 854 which came into effect on September 1, 2023, that focussed on airborne hazards including the reduction of worker exposure to diesel exhaust contaminants.

Full report

Workplace inspection campaigns

Inspection campaigns are part of the MLITSD compliance strategy. Although individual workplaces are not notified in advance, MLITSD will inform sector stakeholders of the upcoming campaign. Inspectors’ findings regarding compliance may impact the number and level of future inspections of individual workplaces.

Focus of the campaign

Mining inspectors visited workplaces and checked if employers were meeting the new requirements set out in Section 182 of Regulation 854, developing and maintaining an airborne hazard management program that came into force on Sept. 1, 2023. Additionally at underground mines, inspectors ensured workplaces were compliant with the requirements for the use of diesel-powered equipment, including the new lower 8-hour time-weighted average exposure of a worker to elemental carbon to limit of 0.12 mg/m3.

Inspectors took appropriate action if contraventions were found under the OHSA or its regulations. This included:

  • writing orders to workplace parties to ensure compliance with legal requirements
  • issuing stop work orders requiring employers to comply before work could continue

Inspection activity summary

Visits to workplaces

  • 134 field visits with 22 support role activities
  • 92 workplaces visited
  • 339 orders and requirements issued
    • 247 contraventions addressed under the OHSA and its regulations
    • 28 stop work orders
    • 49 requirements issued to provide an inspector with workplace information
  • an average of 2.68 contraventions addressed per workplace visited
  • an average of 1.84 contraventions addressed per field visit

Most frequent contraventions addressed

The most frequent contraventions addressed under the OHSA involved:

  • ensuring employers maintain equipment and materials in good condition [s. 25(1)(b)]
  • ensuring that employers take every precaution reasonable in the circumstances for the protection of a worker [s. 25(2)(h)
  • ensuring that employers provide information, instruction and supervision to a worker to protect the health or safety of the worker [s. 25(2)(a)]

A total of 157 contraventions addressed under the Mines and Mining Plants Regulation Regulation (Reg. 854). Orders were issued under the following sections (among others):

  • ensuring that the pulleys of a conveyor are guarded [s. 196(3.1)]
  • ensuring that workplaces have and maintain and Airborne Hazard Management Program [s. 182(1)]
  • ensuring that dust and other material likely to be an airborne hazards is removed [s. 266]
  • ensuring walkway, stairways and ladderways are maintained in a safe condition and free of obstacles [s. 54(1)]

Observations

The results of this campaign indicate that workplace parties need to continue developing and implementing their Airborne Hazard Management Programs, including compliance to ventilation requirements where diesel-powered equipment is used in underground mines.

  • Airborne Hazard Management Programs are a critical component of mining health and safety in Ontario mines and mining plants.
  • Workplaces need to recognize, assess, and control airborne hazards and their associated risks to health to prevent occupational diseases.

Conclusion and next steps

Ministry inspectors will continue to pay attention to airborne hazard management and underground ventilation for diesel-powered equipment.

A key to workplace health and safety in Ontario is the Internal Responsibility System (IRS). Workplace parties are encouraged to work together to identify and control all hazards.

Help for employers

Please contact our health and safety partners for more information.