The Canadian Environmental Protection Act (CEPA) requires the Minister of the Environment and the Minister of Health to prepare and publish a Priority Substances List 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" as defined under Section 11 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
Substances that are assessed as "toxic" as defined under Section 11 of the Act may be placed on Schedule I of CEPA. Consideration can then be given to developing regulations, guidelines, or codes of practice to control any aspect of this substance's life cycle, from the research and development stage through manufacture, use, storage, transport, and ultimate disposal.
The assessment of whether di-n-octyl phthalate (DnOP) is "toxic", as defined under CEPA, was based on the determination of whether it enters or is likely to enter the Canadian environment in a concentration or quantities or under conditions that could lead to exposure of humans or other biota at levels that could cause adverse effects.
Data relevant to the assessment of whether DnOP is "toxic" to the environment under CEPA were identified from existing review documents, published reference texts, and on-line searches conducted between September 1991 and March 1993, of the following commercial databases: CAB Abstracts (1984 to 1993), CHEMICAL ABSTRACTS (1985 to 1991), Chemical Evaluation Search and Retrieval System (CESARS), Hazardous Substances Data Bank (HSDB), IRPTC-LEGAL, and POLLUTION ABSTRACTS (1985 to 1991). Data relevant to the assessment of whether DnOP is "toxic" to the environment obtained after April 1993, have not been included.
To identify toxicological data relevant to the assessment of whether DnOP is "toxic" to human health under CEPA, a background review was prepared under contract by the British Industrial Biological Research Association Toxicology International (BIBRA) in 1991. Information therein was identified on the basis of a literature search of BIBRA's data sources and the online bibliographic databases TOXLINE/TOXLIT, MEDLINE, BIOSIS, National Technical Information System (NTIS) (all, 1962 to 1991), and the Hazardous Substances Data Bank (HSDB) on TOXNET. The following computerized databases were also searched for relevant data in November 1991: Hazardous Substances Data Bank (HSDB), Registry of Toxic Effects of Chemical Substances (RTECS), Integrated Risk Information System (IRIS), Chemical
Carcinogenesis Research Information System (CCRIS), TOXLINE and TOXLIT (all, 1981 to 1991). Dr. A.B. DeAngelo of the U.S. Environmental Protection Agency (U.S. EPA) was also contacted in June 1992, in an attempt to identify additional data relevant to the assessment of the toxicity of DnOP.
To identify data relevant to the estimation of exposure of the general population to DnOP, the following computerized databases were searched in November 1991: Environmental Bibliography (1973 to 1991), Enviroline (1971 to 1991), POLLUTION ABSTRACTS (1970 to 1991), Environment Canada Departmental Library Catalogue (ELIAS) (1991), AQUAREF (1970 to 1991), Canadian Research Index (MICROLOG) (1979 to 1991), and Co-operative Documents Project (CODOC) (1991). Dr. G. Jenkins of the Ontario Ministry of the Environment, Mr. D. Spink of the Alberta Ministry of the Environment, and Mr. H. St.-Martin of Environment Quebec were also consulted in an attempt to identify data on concentrations in environmental media to which humans are exposed (i.e., drinking water). Data relevant to assessment of whether DnOP is "toxic" to human health obtained after August 1992 were not considered for inclusion.
Review articles were consulted where appropriate. However, all original studies that form the basis for determining whether DnOP is "toxic" under CEPA have been critically evaluated by the following Environment Canada staff (entry, and environmental exposure and effects) and Health Canada staff (human exposure and effects on human health):
In this report, a synopsis is presented concerning DnOP that will appear in the Canada Gazette. Section 2.0 is an extended summary of the technical information that is critical to the assessment. The assessment of whether DnOP is "toxic" is presented in Section 3.0. Supporting documentation that presents the technical information in greater detail has also been prepared.
As part of the review and approvals process established by Environment Canada, the environmental sections of this report were peer reviewed by: Dr. Foster Mayer (U.S. EPA, Gulf Breeze, FL), Dr. W.J. Adams (ABC Laboratories, Columbia, MO), and Dr. V. Zitko (Fisheries and Oceans Canada, St. Andrews, NB). Sections related to the effects on human health were approved by the Standards and Guidelines Rulings Committee of the Bureau of Chemical Hazards of Health Canada. The entire Assessment Report was reviewed and approved by the Environment Canada/Health Canada CEPA Management Committee.
Copies of this Assessment Report and the unpublished supporting documentation are available upon request from: