Introduction
The Existing Substances Division (ESD) was established in February 2000 to fill the term very extended on the evaluation of chemicals and other substances in Canada under the revised version of the Canadian Environmental Protection (CEPA). The Division is responsible for identifying and assessing the risks that substances (chemicals) existing in Canada pose to human health, including the approximately 23000 substances identified by the Domestic Substances List (DSL) under CEPA.
Canada is the only country in the world that uses a comprehensive approach of this kind to examine all substances commercially available CEPA Environmental Registry.
CEPA provides a framework for the identification and prioritization of existing substances for the purposes of risk assessment and control or management of those considered to pose a risk to human health or the environment. This framework is comprehensive and based on evidence. It takes into account the aspects (exhibition properties, effects) of a given substance in relation to risk it is likely to raise, in addition to being open, transparent and build on the work done in other forums .
There are four ways to determine the sub-stances subject to a risk assessment:
Categorization of listed substances inside.
Review of the decisions taken by other bodies.
Submitting requests directly to the Minister of the Environment.
Providing advice to Ministers of Health and Environment by advisory committees of experts.
The requirements of CEPA on the renewed rate-uation existing substances are greatly expanded. Thus, we must now systematically take into account the 23000 listed substances inside. These requirements include the addition of a mechanism for the consideration faster substances, whereas previously we put emphasis on a limited number of existing substances deemed to be of priority interest. The status of this report will be studied during the next parliamentary review of CEPA scheduled for 2007.
In addition to the requirement to establish permanent and evaluate lists of priority substances, CEPA-door a requirement that Ministers of Health and Environment to conduct the categorization of all substances on the list of interior by September 2006 and then to undertake the screening assessments and thorough action, as appropriate. Canada is the first country to adopt this legislative requirement for the use of an iterative and systematic approach for establishing priorities for risk management on all existing substances, although at least one other instance (Commission European 2003) has developed legislative proposals with the same sight. This requirement stems partly from the introduction of previous systematic study of all new chemicals (those not used in Canada from 1984 to 1986) under CEPA 1988 and other similar laws country. This requirement extends further in a logical way the experience gained during the selection of the second list of priority substances, which is partly based on the establish-ment of systematic priorities for a sub-set of much broader some 600 substances.
Under CEPA, all substances on the list must be categorized interior by September 2007 (figure 2) to determine those which:
Be present for individuals in Canada the greatest potential for exposure.
Or are persistent and bioaccumulative or are inherently toxic to humans or organisms other than humans.
Categorization, pre-assessment and evaluation of priority interest dessubstances listed interior
Categorization, pre-assessment and evaluation of priority interest desistance listed interior
Health Canada is responsible for determining what are the substances that "the greatest potential for exhibition and those of inherently toxic to humans. Environment Canada (EC) is responsible for determining what are the listed substances that are persistent internal or bioaccumulative and show intrinsic toxicity for organizations other than humans.
The extent possible, categorization should be based on the data available, it is only in the later stages of the screening assessment and the assessment that the holding of tests may be required under the Act. This is attributable mainly with the large number of substances that must be studied and the relatively short time that is prescribed for the completion of phase categorization.
The three phases iterative specified in CEPA as regards the establishment of priorities, for the purposes of risk management on all existing substances. It is the categorical-sation, the prior assessment and the evaluation (Priority Substances), representing increasing levels of complexity. As shown in Figure 2, the objective of the last two phases, ie preliminary assessment and the assessment is to determine whether a given sub-stance is "toxic under CEPA "as defined in section 64 of CEPA, which is the basis for adding the substance to Schedule list of toxic substances and the consideration of options for management risks threatening human health or the environment.
As shown in Figure 2, the second phase iterative prioritization, ie preliminary assessment will be carried out for substances that meet the criteria relating to various aspects of categorization. The content and accuracy of various types of pre-assessments are still being developed. These evaluations prior aimed mainly, as shown in Figure 2, to determine whether certain substances may be set aside (ie. They require no further action) or if there Instead of assigning a priority for a thorough evaluation priority substances. Given the limited objectives of these assessments, it is envisaged that basing decisions on the comparison of estimates of the worst exhibitions and the worst effects that might occur. If the differences are vast, no further action would be required at this stage on the compound. However, if the gaps are low, the substance would be designated to be inscribed on the List of priority substances for the preparation of a thorough assessment, based on more in-depth analyses of available data. The recommendations based on the magnitude of differences exhibition will take into account the relative confidence in the completeness of databases found on exposure and effects, in the context of a prior assessment.
The approach documented in-depth evaluations Priority substances and the reports are available on the Health Canada.
CEPA 1999 only alluded to three phases for the establishment of priorities and evaluation (categorization, prior assessment and priority substances), but it is clear that the consideration systematic priorities for matic assessing and managing the risks of all existing substances in Canada will likely other iterative steps in addition to these three phases defined broadly. Each of the phases outlined in the legislation probably will include one or more other iterative steps prioritization (Figure 2). It is currently developing these different stages simultaneously, putting the emphasis so far on the first step of establishing priorities categorization on various iterations of evaluation prior earlier, on the sub-stances d 'foci.
In the same vein, scores prior reflect different levels of complexity, depending on the nature of the data available, the magnitude of the differences between the estimates of exposure and the worst of the worst effects, and the level of confidence in these differences.
Assessment of risks to health.
It can be concluded that a substance is toxic "under CEPA", based on a preliminary evaluation or assessment of sub-stances of priority interest, or on the review of the decision of another proceeding to ban a sub-stance. As required, develops and implements measures to manage or control the substance.
The assessment of health risks is to:
* Determine what harmful effect critical exposure to a substance can cause;
* Analyze the dose-response relationship;
* Determine the extent to which the population or some subgroups are exposed and then save this exhibition in conjunction with a measure characterizing the dose-response relationship associated with the critical effect observed.
Evaluation is the basic element on which the priority of analysis of options for reducing risks to human health or the environment under the Act is considered in a subsequent phase of Management and distinct risk . Health Canada and CBS are developing options to reduce exposure to substances, often in consultation with stakeholders (see Management Division of Toxic Substances).
It is also mandatory [under section 77 (1) of CEPA] to submit to a public review of the provisional findings and evaluations prior assessments of the risks associated with sub-stances of priority interest. It takes into account the feedback received before putting the finishing touches to these evaluations.
Organization of the Division
There is a need for scientific resources, management and considerable support to categorize the sub-stances on the roster internal within the time prescribed by law, carrying out evaluations and preliminary assessments of the risks that the priority substances pose to human health, and coordinate those functions with our partner in the implementation of CEPA, ie CBS. To meet these responsibilities, the FSD is currently divided into four sections.
The existing substances Sections 1 and 2 are responsible for:
Categorize substances that are persistent or bioac-cumulative on the roster who have domestic inherently toxic to humans;
Carry out preliminary assessment of existing substances and the evaluation of sub-stances of priority interest.
The Evaluation of the exhibition is responsible for:
Categorize the substances listed domestic representing the greatest potential for exposure to humans in Canada;
Perform the analysis of exposure an integral part of the screening assessment or evaluation of the depth of priority substances.
The Section of the scientific coordination of policies and programmes on communications is responsible for:
Provide support in terms of communication and coordination for the activities carried out within the DSE and in collaboration with other groups of
Coordinate the development of new methods to facilitate the implementation of programs, to conduct preliminary assessment of specialized groups of substances and to examine various policy issues relating to the Program of existing substances.
The office of the Existing Substances Division acts as a hub for the planning glob-ale, coordination of the interface and review activities focusing on health-related Existing Substances Program under CEPA 2007.
International Partners
The programme is implemented in collaboration with partners in the field of research, industry and national and international communities, which gives access to a wide range of expertise and viewpoints. For example, the Existing Substances Program coordinates its work with international initiatives to evaluate the effects of chemicals on human health, such as the programme of chemicals controlled by the OECD and the International Programme on Chemical Safety (IPCS) of the World Health Organization (WHO).
The contribution of the DSE initiatives IPCS supports and facilitates the harmonization of health research, risk assessment methodologies and approaches that focus on the management of toxic substances. This encourages the adoption of priorities and objectives for the purposes of implementing the mandate to establish national priorities for systematic all existing substances in Canada. Specifically, the Division has:
* Attended the steering committee PISC on risk assessment to ensure that quality control programs for evaluating substances executed under the IPCS is adequate to ensure that such programs contribute to the realization of the mandate National legislative programme for the evaluation of the list of priority substances (PSL) under CEPA.
* Participated in meetings of the steering committee of the IPCS on harmonization of approaches to assess the risk associated with exposure to chemicals, and other planning meetings on the methodology. Areas of activity include the development of a methodology designed to promote better integration of data on specific compounds to replace the values of certain elements of uncertainty evaluations not related to cancer, and the development of criteria relating to the adequacy of the data collected in order to evaluate the appropriateness of the mode of action carcinogen in humans. The Division is also involved in an exercise aimed at harmonizing the methodology for the assessment of exposure. The benefits of this collaboration with the IPCS of WHO is to optimize the use of available resources to the evaluation and management of industrial chemicals in Canada. This helps to ensure that the risk assessment methodology adopted on the substances of interest priority under CEPA reflects developments and harmony, to the extent possible, with approaches to 'internationally.
* Written for CICAD (Concise International Chemical Assessment Document), a series of reports evalua-tion health and the environment, published by IPCS from WHO and subjected to a process of international peer review. The staff of the DSE has contributed considerably to the preparation of the process of this program to ensure that the outputs thereof reflect the ence experience gained with the national mandate conferred by CEPA. Thus, the Programme of existing sub-stances could get updates on the substances of interest through a process to comply with national standards with the least impact on resources from Health Canada. The participation of the DSE programme of CICAD also provides a suitable framework of peer review for sub-stances of priority interest, which gives access to a cost-effective manner, examinations conducted by experts at 'Internationally, thus promoting the implementation of assessments.
Formatting preliminary assessment of the effects of existing chemicals on human health, perfection-ment of approaches to the evaluation and completion of the pre-assessments provisional effects on the health of a group of seven and polybrominated diphenyl ethers " a group of approximately 60 rons perfluorinated compounds. Preparation of detailed information on all substances for which such records are required (104 of 123 substances) during the pilot phase of the preliminary assessment of sub-stances of the list inside.
Development of a framework for the study of the preponderance of evidence of the relevance of the final results cancerous for humans and participation in the development of a framework designed to integrate the analysis based on the life stages in the risk assessment. Preparation of a preliminary statement of guidance on the use of pharmacokinetic modelling based on physiological data in risk assessment.
Publication of the assessments of the health risks present three substances on the PSL2 (chloroform, butadiene and formaldehyde) in scientific journals and four policy briefs (CICAD) based on the assessment, as part IPCS, substances on the PSL2, carbon disulfide, ethylene oxide, ethylene glycol and acrolein. Publication of three documents on the risk assessment methodology in scientific journals.
Priorities and future plans for 2007-2008
The priorities of the DSE for the coming fiscal year are as follows Refine approaches, based on comments made public on the initial stages of setting priorities for the cat-gorisation substances that have the greatest risk of exposure for humans and with inherent toxicity for humans
Develop approaches for the next steps in setting priorities for the cat-gorisation substances that have the greatest potential for exposure and organic substances having an inherent toxicity. Disseminate scores Advance ethers dypheniques polybrominated, sulfonate perfluo-rooctane and its precursors, and a number of substances on the list domestic representing the greatest risk of exposure According to Health Canada. Develop methods to study the substances included in other data sources, including those of foreign agencies.Develop a joint strategy for coordination, communication and consultation with CBS and the finalization of the joint plans in the long term to 2008.
