Applications of the Ontario Toxics Reduction Act for exposure surveillance


This project aimed to explore ways that data from Ontario’s Toxics Reduction Act (TRA) could be used for an exposure surveillance tool to assess potential exposures to toxic substances. We used an industry sector, regional and substance-specific approach to highlight potential workplace exposures of concern occurring in industries in Ontario. The exposures identified through this surveillance system could be used to target exposure reduction and occupational disease prevention in particular regions or to direct exposure monitoring and enforcement activities in certain geographic areas.

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Surveillance systems that collect data on occupational exposures can provide important information on population-level trends to support the primary prevention of occupational diseases. Exposure surveillance consists of the ongoing assessment and monitoring of chemical use and worker exposures in industries.

Data from exposure surveillance systems can be used to establish priorities for disease prevention strategies among particular groups of hazardous substances, or in particular industrial sectors where these substances are used. These databases can also help researchers conduct ongoing monitoring of the use and emission of particular chemicals in the workplace. Despite progress in the work of surveillance programs like CAREX, a national carcinogen exposure surveillance program, and some provincial exposure registries, not all hazardous occupational exposures are captured and there exist many data gaps.


We used data from 2011 to 2015 from the TRA Program to examine the industrial use of hazardous substances by sector, by region and by substance type to demonstrate potential applications of the TRA data for exposure surveillance. The data were analysed by sector (using 3-digit North American Industry Classification System codes), geographically by Public Health Unit and by carcinogen type (e.g. lung carcinogens).


The results from this project helped to demonstrate ways that data from the TRA could be applied to develop an exposure surveillance system in Ontario. For example, it was found that facilities in the chemical manufacturing sector ranked first among all sectors for reported carcinogen use, using more than 10 million tonnes in the five year period analysed, suggesting exposure surveillance could benefit workers in that sector. It was also found that carcinogen use was highest in Lambton County from 2011 to 2015, representing nearly half of the total carcinogen use for all regions in Ontario, which suggests specific regions where workers are more likely to experience hazardous workplace exposures could benefit from exposure surveillance.

The applications of the TRA data identified in this study could help set priorities for disease prevention by directing future policies towards workers that are employed in certain industrial sectors or in specific regions. Therefore, the TRA Program can help to fill an important gap in occupational exposure surveillance in Ontario using facility-level data to highlight trends occurring at the industry sector or regional scale.


This project was funded by the Ontario Ministry of Labour.

Research Team
Cathy Slavik
OCRC, McMaster University
Sheila Kalenge
Paul A Demers
OCRC, University of Toronto