The Environmental Reporting and Disclosure Bylaw (PDF) lists the following 25 priority substances.

These priority substances are listed in the bylaw because they exist in Toronto’s air at levels of health concern.

Where are these chemicals used?

These chemicals may be used or released in a variety of operations, including chemical manufacturing, food and beverage production, automotive repair and laboratories. For example, trichloroethylene and dichloromethane are common cleaning solvents that may be used in sectors such as manufacturing.

Summary of health effects of each chemical