Screening Assessments (SAs)

• Screening Assessments Currently Available

Substances meeting the categorization criteria proceed to a second phase, a screening assessment (SA).

A screening assessment (SA) involves a more in-depth analysis of a substance to determine whether the substance is “toxic” or capable of becoming “toxic” as defined in CEPA 1999. This determination of toxic consists of integrating the assessment of known or potential exposure of a substance with known or potential adverse effects on the environment. The exposure or potential for exposure of a substance depends on the amount of substance released into the environment and its fate.

The exposure assessment therefore consists of evaluating any known environmental concentrations of a substance, as well as predicting environmental concentrations of a substance from releases resulting from its production, processing, uses and disposal, and its environmental fate evaluated on the basis of intrinsic physical/chemical properties, environmental mobility, and its persistence. The quality and detail of information available to conduct the SA will influence the methods used.

• no further action is taken at this time in respect of the substance, if the SA indicates that the substance does not pose a risk to the environment or human health;
• the substance is added to the CEPA Priority Substances List in order to assess more comprehensively the risks associated with the release of the substance, if the substance is not already on the List; or
• it is recommended that the substance be added to the List of Toxic Substances in Schedule 1 of CEPA, substances on Schedule 1 can be considered for regulatory or other controls.

Under Section 64 of the Act, a substance is "toxic" if it is entering or may enter the environment in a quantity or concentration or under conditions that:

(a) have or may have an immediate or long-term harmful effect on the environment or its biological diversity (b) constitute or may constitute a danger to the environment on which it depends; or (c) constitute or may constitute a danger in Canada to human life or health

As mandated under CEPA 1999, all substances on the DSL must be categorized by September 2006, however there is no mandated deadline for the completion of a screening assessment. Nevertheless, the objective is to assess more substances in an efficient and timely manner.

The information to categorize and prepare the screening level risk assessments will be sought out from a variety or sources including published scientific journals and databases, international reports, computer modelling estimates, and as necessary, through direct contact with industry. Notices under Section 71 of CEPA will be issued to companies making it a requirement for them to provide the requested information if available. Failure to do so may result in legal repercussions.

A pilot project for the screening assessment phase was initiated by Environment Canada and Health Canada. This project identified 123 substances which were anticipated to meet the categorization criteria of 1) persistent and/or bioaccumulative and inherently toxic to non-human organisms or 2) having a high potential for exposure to Canadians.

A comprehensive collection of information on Environment Canada's Screening Assessments appears on the Existing Substances Program CD-ROM. To obtain a copy of the most recent CD-ROM, please send a request to the following address: ESB.DSE@ec.gc.ca.