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Priority Substances Assessment Program

What is Priority Substances Assessment Program (PSAP)?

Assessing the Ecological Risks of Priority Substances Under the Canadian Environmental Protection Act.

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The Canadian Environmental Protection Act (CEPA) requires the Ministers of the Environment and of Health to establish a Priority Substances List (PSL), that identifies substances to be assessed on a priority basis to determine whether they pose a significant risk to the health of Canadians or to the environment. Assessments of substances placed on the PSL are the shared responsibility of Environment Canada and Health Canada. Assessments of the first 44 substances placed on the PSL were completed by February 1994. Following the recommendations of a multi-stakeholder Expert Advisory Panel, 25 substances were added to the PSL, (Extract of the Canada Gazette, Part I, published on December 16, 1995).

The assessment and management of priority substances occurs in two distinct phases. Scientists must first determine whether a substance is “toxic” as defined under Section 64 of CEPA. Under CEPA, a substance is defined as “toxic” if it enters or may enter the environment in amounts or under conditions that may pose a risk to human health, the environment or its biological diversity, or to the environment that supports life. Thus "toxic" in the context of CEPA is a function of both the inherent properties of a substance and of the amounts, concentrations, or nature of entry of the substance in the Canadian environment.

For substances determined to be “toxic”, management options are identified and implemented, in consultation with stakeholders to reduce or eliminate the risks the substances pose to human health or the environment.

The main objective of the Priority Substances Assessment Program is to ensure that accurate and scientifically valid assessments of the Second Priority Substance List (PSL2) substances are completed within the time constraints of the Act. To accomplish this, a process for conducting ecological risk assessments has been developed that will:

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Ecological Risk Assessment Process

The phases of the ecological risk assessment process described below were developed through experience gained in assessing and managing the first PSL substances and through consultations with interested parties.

A "Lead" for each substance has been chosen within Environment Canada who will be responsible for delivery of the ecological risk assessment.

Representatives from other federal government departments and other agencies, will serve as a "Contact Group" to identify their departments' interests in specific substances, names of experts who may wish to contribute to the assessment and relevant information available in their departments. They will also provide feedback at critical steps.

With the assistance of other government departments, environmental non-governmental organizations, industry, academia and other sources, the Lead will establish an "Environmental Resource Group", a group of scientific and technical experts will actively contribute to the assessment. While members may come from any sector, membership will be determined by Environment Canada and limited to those who have the required expertise and commitment to contribute to the assessment process within the timeframe required.

A "Liaison Group" is being established for groups or individuals who would like to receive updates on the progress of the assessments, but may not have time or expertise to participate in a more involved fashion. This website is one of the key mechanisms for communicating the program to this group (PSL2 Updates).

Problem formulation is the first stage in the assessment; its purpose is to establish the goals and focus of the assessment, and to identify any essential data gaps. The problem formulation will be completed by Environment Canada with help from the Environmental Resource Group, Health Canada. Results of the problem formulation will be broadly communicated on this website (PSL2 Updates).

Where data deemed essential to complete the assessment are identified, a strategy to obtain the required information will be developed. The authorities under the Canadian Environmental Protection Act will be used to obtain required existing or new information if voluntary or other means are not suitable.

The draft ecological risk assessment will be reviewed by the Environmental Resource Group, other government departments and by targeted experts. A public scrutiny stage near the end of the assessment process will allow anyone with an interest in the assessment, who has not been part of the process, to provide supporting or conflicting scientific evidence before the department makes its recommendations to the Ministers of the Environment and of Health. (Public Comment Period for Draft Assessment Reports)

As required by section 77 of CEPA, Environment Canada and Health Canada will jointly publish an Assessment report including the conclusion with respect to CEPA "toxic", and a Canada Gazette Notice summarizing the report and announcing the Ministers' intentions. In addition, several documents, such as fact sheets and scientific journal articles, will be published or made available electronically.

For more information about the CEPA Priority Substances Assessment Program please contact:

Existing Substances Division
Science and Risk Assessment Directorate
Environment Canada
Gatineau, Quebec K1A 0H3

Environmental Substances Division
Environmental Health Directorate
Health Canada
Ottawa, Ontario K1A 0L2

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