Priority Substances List Assessment Report for Acrylonitrile

1.0 Introduction

The Canadian Environmental Protection Act, 1999 (CEPA 1999) requires the federal Ministers of Environment and Health to prepare and publish a Priority Substances List (PSL) that identifies substances, including chemicals, groups of chemicals, effluents and wastes, that should be given priority to determine whether they are harmful to the environment or constitute a danger to human health. The Act also requires both Ministers to assess these substances and determine whether they are "toxic" or are capable of becoming "toxic" as defined in Section 64 of the Act, which states:

......a substance is toxic if it is entering or may enter the environment in a quantity or concentration or under conditions that

1. have or may have an immediate or long-term harmful effect on the environment or its biological diversity;
2. constitute or may constitute a danger to the environment on which life depends; or
3. constitute or may constitute a danger in Canada to human life or health.

Substances that are assessed as "toxic" as defined in Section 64 may be placed on Schedule I of the Act and considered for possible risk management measures, such as regulations, guidelines, pollution prevention plans or codes of practice to control any aspect of their life cycle, from the research and development stage through manufacture, use, storage, transport and ultimate disposal.

Based on an initial screening of readily accessible information, the rationale for assessing acrylonitrile provided by the Ministers' Expert Advisory Panel on the Second Priority Substances List (Ministers' Expert Advisory Panel, 1995) was as follows:

People living within a few kilometres of sites where acrylonitrile is used may have significant exposure. The compound can also be released from products made with polyacrylic fibre or from vehicle exhaust and cigarette smoke. Acrylonitrile is carcinogenic and genotoxic in animals, and there is some evidence that it is carcinogenic in humans. An assessment is needed to characterize the extent of exposure and associated risks for humans and the environment in Canada.

Descriptions of the approaches to assessment of the effects of Priority Substances on the environment and human health are available in published companion documents. The document entitled "Environmental Assessments of Priority Substances under the Canadian Environmental Protection Act. Guidance Manual Version 1.0 - March 1997" (Environment Canada, 1997a) provides guidance for conducting environmental assessments of Priority Substances in Canada. This document may be purchased from:

Environmental Protection Publications
Environmental Technology Advancement Directorate
Environment Canada
Ottawa, Ontario
K1A 0H3

It is also available on the Internet at www.ec.gc.ca/cceb1/eng/psap.htm under the heading "Technical Guidance Manual." It should be noted that the approach outlined therein has evolved to incorporate recent developments in risk assessment methodology, which will be addressed in future releases of the guidance manual for environmental assessments of Priority Substances.

The approach to assessment of effects on human health is outlined in the following publication of the Environmental Health Directorate of Health Canada: "Canadian Environmental Protection Act - Human Health Risk Assessment for Priority Substances" (Health Canada, 1994), copies of which are available from:

Environmental Health Centre
Room 104
Health Canada
Tunney's Pasture
Ottawa, Ontario
K1A 0L2

or on the Environmental Health Directorate publications web site (www.hc-sc.gc.ca/ehp/ehd/catalogue/bch.htm). The approach is also described in an article published in the Journal of Environmental Science and Health -Environmental Carcinogenesis & Ecotoxicology Reviews (Meek et al., 1994). It should be noted that the approach outlined therein has evolved to incorporate recent developments in risk assessment methodology, which are described on the Environmental Substances Division web site (www.hc-sc.gc.ca/ehp/ehd/bch/env_contaminants/psap/psap.htm) and which will be addressed in future releases of the approach paper for the assessment of effects on human health.

The search strategies employed in the identification of data relevant to the assessment of potential effects on the environment (prior to May 1998) and on human health (prior to April 1998) are presented in Appendix A. Review articles were consulted where appropriate. However, all original studies that form the basis for determining whether acrylonitrile is "toxic" under CEPA have been critically evaluated by staff of Environment Canada (entry and environmental exposure and effects) and Health Canada (human exposure and effects on human health).

An Environmental Resource Group was established by Environment Canada to assist in the preparation and review of the environmental sections of the Assessment Report and the supporting documentation (Environment Canada, 1998). Members were selected based on their expertise, notably in the areas of toxicology, process and automotive chemistry and engineering, environmental monitoring and environmental chemistry. Members included:

• B. Benjey, U.S. Environmental Protection Agency
• D. Brooke, United Kingdom Department of the Environment
• L. Brownlee, Environment Canada
• N. Bunce, University of Guelph
• H. Campbell, Waste Water Technology Centre
• P. Cureton, Environment Canada
• M. Day, National Research Council of Canada
• F. Edgecomb, Canadian Plastics Industry
• J. Girard, Environment Canada
• L. Graham, Environment Canada
• P. Paine, Environment Canada
• A. Pope, U.S. Environmental Protection Agency
• I. Pratt, Health and Safety Authority, Ireland
• J. Prinsen, Environment Canada
• J. Sherry, Environment Canada
• M. Wright, Bayer-Rubber Division

The environmental assessment was led by Cureton.

Environmental sections of the Assessment Report and the supporting documentation (Environment Canada, 1998) were also reviewed by internal reviewers at Environment Canada -namely, R. Hoff, K. Lloyd, J. Pasternak, E. Rezek and P. Thompson. External reviewers were W.Broadworth (G.E. Plastics Canada), N.Karellas (Ontario Ministry of the Environment), R. Keefe (Imperial Oil), A. Kerr (Bayer-Rubber Division), J. Murray (The Acrylonitrile Group), V. Nabholz (U.S. Environmental Protection Agency), J.Pellerin Université du Québec à Rimouski), J.Soule (DuPont Canada) and A. Tomlin (Agriculture and Agri-Food Canada).

The health-related sections of this Assessment Report and supporting documentation were prepared by the following staff of Health Canada:

• D. Blakey
• D. Koniecki
• G. Long
• M.E. Meek

Sections of the Assessment Report and supporting documentation were reviewed by R. Beauchamp, R. Liteplo and L. Turner of the Environmental Substances Division of Health Canada. M. Walker of the Biostatistics and Computer Applications Division of Health Canada provided statistical support. The health-related sections of the Assessment Report and the supporting documentation were based in part upon a review of the epidemiological data, prepared under contract by J. Siemiatycki of the Institut Armand-Frappier.

In order to address primarily adequacy of coverage, sections of the supporting documentation pertaining to human health were reviewed externally by:

• J.J. Collins, Solutia Inc., St. Louis, Missouri
• B. Ghanayem, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina
• G.L. Kedderis, Chemical Industry Institute of Toxicology, Research Triangle Park, North Carolina
• N. Krivanek, E.I. du Pont de Nemours & Co., Newark, Delaware
• D. Strother, BP Chemicals Inc., Cleveland, Ohio
• J. Whysner, American Health Foundation, Valhalla, New York

Accuracy of reporting, adequacy of coverage and defensibility of conclusions with respect to hazard characterization and dose-response analyses were considered in written review by staff of the Information Department of BIBRA International and at a panel meeting of the following members, convened by Toxicology Excellence for Risk Assessment (TERA) on November 17, 1998, in Cincinnati, Ohio:

• M.J. Aardema, The Procter & Gamble Co.
• M.L. Dourson, TERA
• S. Felter, The Procter & Gamble Co.
• M.A. Friedman, private consultant
• M.L. Gargas, ChemRisk Division, McLaren/Hart
• R.G. Tardiff, The Sapphire Group, Inc.
• V.T. Vu, U.S. Environmental Protection Agency
• V. Walker, New York State Department of Health

The health-related sections of the Assessment Report were reviewed and approved by the Health Protection Branch Risk Management meeting of Health Canada.

The entire Assessment Report was reviewed and approved by the Environment Canada/Health Canada CEPA Management Committee.

A draft of the Assessment Report was made available for a 60-day public comment period (June 26 to August 24, 1999) (Environment Canada and Health Canada, 1999). Following consideration of comments received, the Assessment Report was revised as appropriate. A summary of the comments and thier responses are available on the Internet at:

www.ec.gc.ca/cceb1/eng/final/index_e.html

The text of the Assessment Report has been structured to address environmental effects initially (relevant to determination of "toxic" under Paragraphs 64(a) and (b)), followed by effects on human health (relevant to determination of "toxic" under Paragraph 64(c)).

Copies of this Assessment Report are available upon request from:

Inquiry Centre
Environment Canada
Main Floor, Place Vincent Massey
351 St. Joseph Blvd. Hull, Quebec
K1A 0H3

or on the Internet at:

www.ec.gc.ca/cceb1/eng/final/index_e.html

Unpublished supporting documentation, which presents additional information, is available upon request from:

Commercial Chemicals Evaluation Branch
Environment Canada
14th Floor, Place Vincent Massey
351 St. Joseph Blvd.
Hull, Quebec
K1A 0H3

or

Environmental Health Centre
Room 104
Health Canada
Tunney's Pasture
Ottawa, Ontario
K1A 0L2