Priority Substances List Assessment Report for Acetaldehyde

1.0 Introduction

The Canadian Environmental Protection Act, 1999 (CEPA 1999) requires the federal Ministers of the Environment and of Health to prepare and publish a Priority Substances List (PSL) that identifies substances, including chemicals, groups of chemicals, effluents and wastes, that may be 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 initial screening of readily accessible information, the rationale for assessing acetaldehyde provided by the Ministers' Expert Advisory Panel on the Second Priority Substances List (Ministers' Expert Advisory Panel, 1995) was as follows:

This compound is used in Canada primarily in the manufacture of other chemical substances and as a finishing agent. Humans are likely to be exposed to acetaldehyde from airborne pollution. Direct human exposure may also result from other uses. Acetaldehyde is not persistent or bioaccumulative. Under laboratory conditions, it is carcinogenic when inhaled by rats and hamsters. It induces chromosome abnormalities in rodents. Information on this substance has been gathered, reviewed and evaluated by an international group of experts. An assessment is required to determine human exposure to acetaldehyde in the Canadian environment and its associated risks.

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 and 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 January 1999) and 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 acetaldehyde 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).

Preparation of the environmental components of the assessment was led by R. Chénier with support from M. Eggleton and was coordinated by A. Bobra on behalf of Environment Canada. Sections of the Assessment Report and the supporting documentation (Environment Canada, 1999) related to the environmental assessment of acetaldehyde were prepared or reviewed by the members of the Environmental Resource Group, established by Environment Canada to support the environmental assessment:

• A. Bobra, AMBEC Environmental Consultants
• B. Brownlee, Environment Canada
• N. Bunce, University of Guelph
• R. Chénier, Environment Canada
• T. Currah, Oxychem Durez
• T. Dann, Environment Canada
• E. Dowdall, Environment Canada
• M. Eggleton, Environment Canada
• J. Gagnon, Natural Resources Canada
• J. Girard, Environment Canada
• G. Granville, Shell Canada Chemical Co.
• R. Keefe, Imperial Oil
• G. Rideout, Environment Canada
• A. Stelzig, Environment Canada
• M. Tushingham, Environment Canada
• J. Wittwer, Environment Canada

Environmental sections of the Assessment Report and supporting documentation (Environment Canada, 1999) were also reviewed by S. Abernethy (Ontario Ministry of the Environment), D. Ames (California Environmental Protection Agency), G. Bird (Natural Resources Canada), L. Brownlee (Environment Canada), J. Collins (California Environmental Protection Agency), A. Day (Celanese Canada Inc.), S. Dungey (United Kingdom Environment Agency), L. McCarty (L.S. McCarty Scientific Research and Consulting), G. Obe (Essen Polytechnic University), L. Seed (Health Canada) and P. Shepson (Purdue University).

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

• R. Beauchamp
• R. Gomes
• M.E. Meek

Sections of the supporting documentation on genotoxicity were reviewed by D. Blakey of the Environmental and Occupational Toxicology Division of Health Canada. Sections of the supporting documentation pertaining to human health were reviewed externally by R. Keefe (Imperial Oil) and C. Chopra (Bio-Tox Research Limited), primarily to address adequacy of coverage. 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 in Risk Assessment (TERA) on September 30, 1997, in Cincinnati, Ohio:

• K. Blackburn, Procter & Gamble
• M. Bogdanffy, DuPont
• M. Dourson, TERA
• R. Keenan, ChemRisk Division of McLaren/Hart
• G. Leikauf, University of Cincinnati
• R. Manning, Georgia Department of Natural Resources
• E. Ohanian, U.S. Environmental Protection Agency
• K. Poirier, Procter & Gamble
• A. Renwick, University of Southampton
• L. Rosato, Millennium Petrochemical
• L. Sirinek, Ohio Environmental Protection Agency

Helpful written comments were also received from A. Jarabek of the U.S. Environmental Protection Agency.

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 (August 14 to October 13, 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 their responses is 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