M10 PM Chemical Hazard Identification, Classification and Communication
Monday, 14 November 2005: 1:50 PM - 5:30 PM in 341-342

(GAU-1117-742755) Ecological Categorization of Organometallic Substances on Canada^,s Domestic Substances List.

Gauthier, J.¹, Costa, P.¹, Couillard, Y.¹, Eggleton, M.¹, Goulet, R.¹, Rudnitski, K.¹, Schnabel, S.¹, ¹ Environment Canada, Gatineau, Québec, Canada

ABSTRACT- The Canadian Environmental Protection Act, 1999 (CEPA 99), requires the Ministers of Environment and Health to categorize, based on human health and ecological considerations, the 23 000 commercial substances on the Domestic Substances List (DSL) by September 2006. Ecological categorization consists of reviewing available data and identifying substances that meet established criteria for persistence and/or bioaccumulation and inherent toxicity to aquatic organisms. Substances that meet categorization criteria will then be considered for screening assessment under CEPA 99 to determine whether they pose a risk to Canadians and/or their environment. About 1100 substances on Canada^,s DSL have been classified as organometallics, including 850 discrete organometallics and 260 unknown or variable complex mixtures. The approach used for the categorization of these organometallic substances essentially combines principles used in the categorization of organic and inorganic substances. Data on metal-containing transformation products were additionally considered. In contrast to other classes of substances on the DSL, there are very few empirical data available and prediction techniques such as quantitative structure-activity relationships (QSARs) have not been extensively developed for organometallics. To aid in the categorization of data-poor organometallics, category approaches were developed based on chemical analogy and weight of evidence. This presentation further describes these approaches and Environment Canada^,s preliminary categorization decisions for organometallics on the DSL. Interested parties are encouraged to submit complementary information to help refine decisions by December 2005. Additional considerations for the priority-setting of DSL substances for screening assessments are mentioned.

Key words: Ecological, Categorization, Organometallics, Canada