Chemicals of Mutual Concern (Annex 3)

An industrial area on the St. Clair River near Sarnia, Ontario. Credit: Environment and Climate Change Canada.

Chemical pollution can harm aquatic ecosystems and negatively impact habitats and biodiversity throughout the Great Lakes. Some chemicals are persistent and can bioaccumulate in the food web, exposing humans to potentially harmful chemicals through fish consumption.

In 2016, Canada and the U.S. designated the following eight chemicals as the first set of Chemicals of Mutual Concern (CMC) under the 2012 Great Lakes Water Quality Agreement (GLWQA):

Any chemical nominated as a CMC will be reviewed according to the Binational Screening Criteria for Nominated CMCs, developed by Environment and Climate Change Canada (ECCC) and the U.S. Environmental Protection Agency (USEPA) to provide a consistent framework for reviewing nominated CMCs under the GLWQA.

Purpose of the Chemicals of Mutual Concern Annex

Through the Chemicals of Mutual Concern Annex of the 2012 Great Lakes Water Quality Agreement, Canada and the United States have committed to:

“… contribute to the achievement of the General and Specific Objectives of this Agreement by protecting human health and the environment through cooperative and coordinated measures to reduce the anthropogenic release of chemicals of mutual concern into the Waters of the Great Lakes.”

Key Commitments

Canada and the United States agree to:

  • Identify chemicals of mutual concern that originate from anthropogenic (human) sources, and that are agreed to by both countries as being potentially harmful to human health or the environment;
  • Target these chemicals of mutual concern for action by preparing binational strategies and coordinating the development and application of domestic water quality standards, objectives, criteria and guidelines, as appropriate;
  • Reduce anthropogenic releases of chemicals of mutual concern and products containing chemicals of mutual concern throughout their entire life cycles;
  • Promote the use of safer chemical substances and the use of technologies that reduce or eliminate the uses and releases of chemicals of mutual concern;
  • Continue progress toward the sound management of chemicals of mutual concern using approaches that are accountable, adaptive and science-based;
  • Monitor and evaluate the progress and effectiveness of pollution prevention and control measures for chemicals of mutual concern and adapt management approaches as necessary;
  • Regularly exchange information on monitoring, surveillance, research, technologies, and measures for managing chemicals of mutual concern; and
  • Coordinate and collaborate with various stakeholders on science priorities, research, surveillance and monitoring activities in the Great Lakes basin ecosystem.

For additional information on the focus of actions under this Annex, consult the current Priorities for Science and Action. The Priorities are based on an evaluation of the State of the Great Lakes, with input from the Great Lakes Executive Committee, participants at the Great Lakes Public Forum, and recommendations of the International Joint Commission.

Every six months, progress on this annex is reported at the Great Lakes Executive Committee meetings. Accomplishments will be described in the Progress Report of the Parties every three years.


This annex is implemented by a sub-committee co-led by ECCC and the USEPA. Organizations represented include:

  • Chiefs of Ontario
  • Great Lakes Indian Fish and Wildlife Commission
  • Indiana Department of Environmental Management
  • Minnesota Department of Health
  • Minnesota Pollution Control Agency
  • Ontario Ministry of the Environment, Conservation and Parks
  • United States National Oceanic and Atmospheric Administration
  • Wisconsin Department of Natural Resources

The sub-committee is supported by an extended sub-committee that involves additional organizations and experts beyond the GLEC membership. As required, time-limited task teams will focus efforts on a priority issue or project, and will be disbanded when work is complete.