Priority Substances List Assessment Report for Hexachlorobutadiene

Environment Canada
Health Canada
2001
ISBN: 0-662-29297-9
Cat. No.: En40-215/58E

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Canadian Environmental Protection Act, 1999

Table of Contents

• List of Acronyms and Abbreviations
• Synopsis
• 1.0 Introduction
• 2.0 Summary of Information Critical to Assessment of "Toxic" Under CEPA 1999
  • 2.1 Identity and physical/chemical properties
  • 2.2 Entry characterization
    • 2.2.1 Production, importation and use
    • 2.2.2 Sources and releases
      • 2.2.2.1 Natural sources
      • 2.2.2.2 Anthropogenic sources
  • 2.3 Exposure characterization
    • 2.3.1 Environmental fate
      • 2.3.1.1 Air
      • 2.3.1.2 Water
      • 2.3.1.3 Sediment
      • 2.3.1.4 Soils
      • 2.3.1.5 Biota
      • 2.3.1.6 Environmental partitioning
    • 2.3.2 Environmental concentrations
      • 2.3.2.1 Air
      • 2.3.2.2 Drinking water
      • 2.3.2.3 Surface water
      • 2.3.2.4 Sediments
      • 2.3.2.5 Soils
      • 2.3.2.6 Biota
      • 2.3.2.7 Food
      • 2.3.2.8 Multimedia exposure study
  • 2.4 Effects characterization
    • 2.4.1 Ecotoxicology
      • 2.4.1.1 Pelagic organisms
      • 2.4.1.2 Benthic organisms
    • 2.4.2 Abiotic atmospheric effects
    • 2.4.3 Experimental animals and in vitro
      • 2.4.3.1 Acute toxicity
      • 2.4.3.2 Short-term and subchronic toxicity
      • 2.4.3.3 Chronic toxicity and carcinogenicity
      • 2.4.3.4 Genotoxicity
      • 2.4.3.5 Reproductive and developmental toxicity
      • 2.4.3.6 Neurological effects and effects on the immune system
      • 2.4.3.7 Toxicokinetics and mechanism of action
    • 2.4.4 Humans
• 3.0 Assessment of "Toxic" under CEPA 1999
  • 3.1 CEPA 1999 64(a): Environment
    • 3.1.1 Assessment endpoints
    • 3.1.2 Environmental risk characterization
      • 3.1.2.1 Pelagic organisms
      • 3.1.2.2 Benthic organisms
      • 3.1.2.3 Sources of uncertainty
      • 3.1.2.4 Conclusion
  • 3.2 CEPA 1999 64(b): Environment upon which life depends
  • 3.3 CEPA 1999 64(c): Human health
    • 3.3.1 Estimated population exposure
    • 3.3.2 Hazard characterizat ion
    • 3.3.3 Dose-response analyses
    • 3.3.4 Human health risk characterization
    • 3.3.5 Uncertainties and degree of confidence in human health risk characterization
  • 3.4 Conclusions
  • 3.5 Considerations for follow-up (further action)
• 4.0 References
• Appendix A Search Strategies Employed for Identification of Relevant Data

List of Tables

• Table 1 Risk quotient for pelagic organisms
• Table 2 Summary of risk quotients for freshwater benthic organisms
• Table 3 Estimated exposure of the general population to HCBD
• Table 4 Point versus probabilistic estimates of exposure to HCBD via inhalation
• Table 5 Critical studies and effect levels for renal toxicity in experimental animals exposed to HCBD via ingestion

List of Figures

• Figure 1 Structure of HCBD
• Figure 2 Cumulative density function for HCBD in St. Clair River sediments (0-5 cm)