50-1443-eng-cov.qxd 5/18/00 19:56 Page 1 Environment Environnement Canada Canada Health Santé Canada Canada Canadian Environmental Protection Act, 1999 PRIORITY SUBSTANCES LIST ASSESSMENT REPORT Acrylonitrile Canada 50-1443-eng-cov.qxd 5/18/00 19:56 Page 2 Canadian Cataloguing in Publication Data Priority substances list assessment report: acrylonitrile (Priority substances list assessment report) Issued also in French under title: Liste des substances d'intérêt prioritaire, rapport d'évalua- tion, acrylonitrile. Canadian Environmental Protection Act. Includes bibliographical references. Co-published by Health Canada. Issued also on the Internet. ISBN 0-662-28587-5 Cat. no. En40-215/49E 1. Acrylonitrile -- Toxicity testing -- Canada. 2. Acrylonitrile -- Environmental aspects -- Canada. 3. Environmental monitoring -- Canada. I. Canada. Environment Canada. II. Canada. Health Canada. III. Series. TD887.A37P74 2000 363.738'4 C00-980073-5 Additional information can be obtained at Environment Canadas Web site at www.ec.gc.ca or from the Inquiry Centre at 1-800-668-6767. © Minister of Public Works and Government Services 2000 50-1443-eng-cov.qxd 5/18/00 19:56 Page 3 Canadian Environmental Protection Act, 1999 PRIORITY SUBSTANCES LIST ASSESSMENT REPORT Acrylonitrile Environment Canada Health Canada May 2000 50-1443-eng.qxd 5/29/00 14:48 Page 1 TABLE OF CONTENTS SYNOPSIS .................................................................................................................... 1 1.0 INTRODUCTION ................................................................................................ 3 2.0 SUMMARY OF INFORMATION CRITICAL TO ASSESSMENT OF “TOXIC” UNDER CEPA 1999.......................................................................................... 7 2.1 Identity and physical/chemical properties ............................................ 7 2.2 Entry characterization ............................................................................ 7 2.2.1 Production, importation and uses ........................................................ 7 2.2.2 Sources and releases ............................................................................ 7 2.2.2.1 Natural sources .................................................................. 7 2.2.2.2 Anthropogenic sources ...................................................... 7 2.2.2.2.1 Organic chemicals industry .......................... 9 2.2.2.2.2 Vehicles .......................................................... 9 2.2.2.2.3 Municipal wastewater treatment .................. 9 2.2.2.2.4 Transboundary sources.................................. 10 2.2.2.2.5 Pesticide use .................................................. 10 2.3 Exposure characterization ...................................................................... 10 2.3.1 Environmental fate ................................................................................ 10 2.3.1.1 Air ...................................................................................... 10 2.3.1.2 Water.................................................................................. 11 2.3.1.3 Soil and sediment .............................................................. 11 2.3.1.4 Biota .................................................................................. 11 2.3.1.5 Environmental partitioning................................................ 11 2.3.2 Environmental concentrations .............................................................. 12 2.3.2.1 Ambient air ........................................................................ 12 2.3.2.2 Indoor air............................................................................ 15 2.3.2.3 Surface water and groundwater ........................................ 15 2.3.2.4 Drinking water .................................................................. 16 2.3.2.5 Soil and sediment .............................................................. 16 2.3.2.6 Biota .................................................................................. 16 2.3.2.7 Food .................................................................................. 16 2.3.2.8 Multimedia study .............................................................. 17 2.4 Effects characterization............................................................................ 17 2.4.1 Ecotoxicology ...................................................................................... 17 2.4.1.1 Terrestrial organisms.......................................................... 17 2.4.1.2 Aquatic organisms ............................................................ 18 2.4.1.3 Mode of action .................................................................. 20 2.4.1.4 Microbial populations........................................................ 20 2.4.2 Abiotic atmospheric effects .................................................................. 20 2.4.3 Experimental animals and in vitro ...................................................... 21 PSL ASSESSMENT REPORT — ACRYLONITRILE iii 50-1443-eng.qxd 5/29/00 14:48 Page 2 2.4.3.1 Acute toxicity .................................................................... 21 2.4.3.2 Short-term toxicity ............................................................ 22 2.4.3.3 Subchronic toxicity............................................................ 22 2.4.3.4 Chronic toxicity and carcinogenicity ................................ 22 2.4.3.4.1 Inhalation ...................................................... 22 2.4.3.4.2 Drinking water .............................................. 23 2.4.3.4.3 Gavage .......................................................... 28 2.4.3.5 Genotoxicity ...................................................................... 29 2.4.3.5.1 In vitro studies .............................................. 29 2.4.3.5.2 In vivo studies................................................ 30 2.4.3.6 Reproductive and developmental toxicity ........................ 31 2.4.3.7 Neurological effects and effects on the immune system.................................................................. 32 2.4.3.8 Toxicokinetics and mode of action.................................... 32 2.4.3.8.1 Toxicokinetics ................................................ 32 2.4.3.8.2 Mode of action .............................................. 33 2.4.4 Humans ................................................................................................ 34 3.0 ASSESSMENT OF “TOXIC” UNDER CEPA 1999 .............................................. 37 3.1 CEPA 1999 64(a): Environment.............................................................. 37 3.1.1 Assessment endpoints............................................................................ 37 3.1.1.1 Terrestrial organisms.......................................................... 37 3.1.1.2 Aquatic organisms ............................................................ 37 3.1.2 Environmental risk characterization .................................................... 38 3.1.2.1 Terrestrial organisms.......................................................... 38 3.1.2.2 Aquatic organisms ............................................................ 38 3.1.2.3 Discussion of uncertainty .................................................. 39 3.2 CEPA 1999 64(b): Environment on which life depends........................ 40 3.3 CEPA 1999 64(c): Human health .......................................................... 40 3.3.1 Estimated population exposure ............................................................ 40 3.3.2 Hazard characterization ...................................................................... 44 3.3.2.1 Effects in humans .............................................................. 44 3.3.2.2 Effects in experimental animals ........................................ 44 3.3.3 Dose–response analyses........................................................................ 46 3.3.3.1 Effects in humans .............................................................. 46 3.3.3.2 Effects in experimental animals ........................................ 47 3.3.3.2.1 Non-neoplastic effects.................................... 47 3.3.3.2.2 Cancer............................................................ 48 3.3.4 Human health risk characterization .................................................... 50 3.3.5 Uncertainties and degree of confidence in human health risk characterization .................................................................................... 53 3.4 Conclusions................................................................................................ 54 3.5 Considerations for follow-up (further action) ...................................... 55 iv PSL ASSESSMENT REPORT — ACRYLONITRILE 50-1443-eng.qxd 5/29/00 14:48 Page 3 4.0 REFERENCES .................................................................................................... 57 APPENDIX A SEARCH STRATEGIES EMPLOYED FOR IDENTIFICATION OF RELEVANT DATA ............................................................................ 75 LIST OF TABLES TABLE 1 Physical and chemical properties of acrylonitrile ........................................................ 8 TABLE 2 Demand for acrylonitrile in Canada, 1990–1997 ........................................................ 8 TABLE 3 Predicted concentrations of acrylonitrile in southern Ontario from ChemCAN3 modelling with various half-lives in air given (reported releases under Section 16 of