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Blitz Targets Mine Ventilation Hazards

  • Issued: October 17, 2011
  • Content last reviewed: October 2011
  • See also: Bulletin | Mining

During October and November, mining inspectors will focus on hazards involving ventilation systems at selected underground mines across Ontario.

The increased enforcement is part of the province’s Safe At Work Ontario strategy, launched in June 2008.

Ministry of Labour inspectors will check that mine ventilation systems are being maintained and provide an adequate supply of clean air. They will also check that diesel equipment is being properly maintained and that employers are regularly testing the air quality in underground mines.


Ventilation hazards pose a serious concern in underground mines, many of which operate diesel equipment. The air in poorly ventilated mines can contain toxins, which can cause occupational disease and even death.

Between 2005 and 2009, 176 workers died and another 36 workers developed occupational diseases related to respiratory illnesses in the mining sector, according to claim information from the Workplace Safety and Insurance Board.

Between January 1, 2009 and March 31, 2011, ministry mining inspectors issued the following ventilation-related orders to underground mine operators:

  • 79 orders for not providing adequate ventilation, and
  • 35 orders for removal of dust or other hazardous airborne material.

Ventilation hazards include:

  • Poorly maintained underground mechanical ventilation systems that are not providing adequate clean air supplies and not removing toxic substances such as diesel, dust and other airborne substances, and
  • Poorly maintained diesel equipment that create high levels of emissions.

Blitz Focus

Inspectors will target underground mines that use diesel equipment. This includes:

  • Mines with large fleets of diesel equipment operating in the underground environment
  • Recently reopened or new mines operating diesel equipment
  • Mines where previous ventilation concerns were observed, and
  • Mines with a poor health and safety compliance history.

Inspectors will check on two types of equipment:

  • Ventilation systems used to deliver fresh air to underground mines, and
  • Diesel equipment used for underground transportation of workers and materials and blasting of rock.

Inspectors will take enforcement action, as appropriate, for any contraventions found under the Occupational Health and Safety Act and its regulations.


Mining inspectors will focus on the following key priorities:

  • Ventilation Systems: Inspectors will check that ventilation systems are providing an adequate clean air supply in underground mines. This includes auxiliary ventilation systems which are used to bolster the air quality in areas where diesel equipment is operated.
  • Diesel Equipment: Inspectors will check that diesel equipment is being properly maintained. This equipment is used for underground transportation of workers and materials and blasting of rock.
  • Workplace Air Sampling: Inspectors will check that employers are regularly testing the air in underground mines to ensure concentrations of toxic substances do not exceed levels set in Regulations for Mines and Mining Plants.

Matt Blajer, Communications Branch, 416-326-7405
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