Vol. 145, No. 32 — August 6, 2011
ARCHIVED — Order Adding Toxic Substances to Schedule 1 to the Canadian Environmental Protection Act, 1999
Canadian Environmental Protection Act, 1999
Department of the Environment and Department of Health
(This statement is not part of the Order.)
Issue and objectives
Canadians depend on chemical substances that are used in hundreds of goods, from medicines to computers, fabrics, and fuels. Unfortunately, some chemical substances can negatively affect our health and environment when released in a certain quantity or concentration in the environment. Scientific assessments of the impact of human and environmental exposure have determined that a number of these substances constitute or may constitute a danger to human health or to the environment as per the criteria set out under section 64 of the Canadian Environmental Protection Act, 1999 (CEPA 1999).
The objective of the proposed Order Adding Toxic Substances to Schedule 1 to the Canadian Environmental Protection Act, 1999 (hereinafter referred to as the proposed Order) made under subsection 90(1) of CEPA 1999, is to add polychlorinated naphthalenes, which have the molecular formula C10H8-nCln, in which n is greater than 1, to the List of Toxic Substances in Schedule 1 of CEPA 1999.
This addition enables the development of regulatory instruments for these substances under CEPA 1999. The Ministers may, however, choose to develop non-regulatory instruments to manage human health and environmental risks posed by these substances.
Description and rationale
Approximately 23 000 substances (often referred to as “existing” substances) were reported to be in use in Canada between January 1, 1984, and December 31, 1986. These substances are found on the Domestic Substances List (DSL), but many of these have never been assessed as to whether they meet any of the toxicity criteria set out in section 64 of CEPA 1999. Section 73 of CEPA 1999 requires that substances on the DSL be “categorized” to determine which of them pose the greatest potential for exposure to the general population as well as those that are persistent or bioaccumulative and inherently toxic to human beings or non-human organisms. Pursuant to section 74 of CEPA 1999, substances that have met categorization criteria must undergo an assessment to determine whether they meet any of the criteria set out in section 64.
The Minister of the Environment and the Minister of Health (the Ministers) completed the categorization exercise in September 2006. Of the approximately 23 000 substances on the DSL, 4 300 were identified as needing further attention.
“Naphthalene, chloro derivatives,” Chemical Abstracts Service Registry Number (see footnote 1) 70776-03-3, can be described as a variable chemical mixture that covers the chemical class of chlorinated naphthalenes. A risk assessment of chlorinated naphthalenes was conducted partially because they were identified as a high priority for assessment of ecological risk and were found to meet the categorization criteria for persistence, bioaccumulation potential and inherent toxicity to aquatic organisms. Additionally, chlorinated naphthalenes were assessed because their production and usage have been banned or restricted in various countries of the Organisation for Economic Co-operation and Development (OECD), including Switzerland, Germany and Japan. As well, recent scientific studies (see footnote 2) indicate the presence of chlorinated naphthalenes in the Arctic and Antarctica, suggesting that chlorinated naphthalenes are persistent in air and subject to long-range atmospheric transport. These substances were also recently added to the Protocol on Persistent Organic Pollutants (POPs) under the international Convention on Long-Range Transboundary Air Pollution (CLRTAP).
Information supporting the assessment was collected from stakeholders, through consultations and a voluntary industry survey and other available information such as the scientific literature.
Based on the information obtained, a screening assessment was conducted in order to assess whether these substances meet the ecological criteria set out in section 64 of CEPA 1999, that is to say, whether the substances are entering or may enter the environment in a quantity or concentration or under conditions that
- have or may have an immediate or long-term harmful effect on the environment or its biological diversity; or
- constitute or may constitute a danger to the environment on which life depends.
When a substance is found to meet one or more of the criteria set out in section 64, a recommendation can be made that the substance be added to Schedule 1 of CEPA 1999.
The addition of substances to Schedule 1 of CEPA 1999 allows the Ministers under section 91 of CEPA 1999 to develop risk management instruments in order to meet their obligations under the Act (to propose a regulation or other regulatory instruments within two years and to finalize the instrument 18 months later). The Act enables the development of risk management instruments (such as regulations, guidelines or codes of practice) to protect the environment and human health. These instruments can be developed for any aspect of the substance’s life cycle from the research and development stage through manufacture, use, storage, transport and ultimate disposal or recycling. A proposed risk management approach document, which provides an indication of where the Government will focus its risk management activities, has been prepared for polychlorinated naphthalenes.
The draft ecological screening assessment for chlorinated naphthalenes was published on the chemical substances Web site, and the statement recommending addition to Schedule 1 was published in the Canada Gazette, Part I, on July 18, 2009, for a 60-day public comment period (www.chemicalsubstanceschimiques.gc.ca/challenge-defi/naphthalenes-eng.php).
The assessment summary, conclusions and an overview of the public comments received during the public comment period are presented below.
Substance description, assessment summary and conclusions
Chlorinated naphthalenes are characterized by two fused benzene rings with varying numbers of attached chlorine atoms. They are a group of 75 substances which are divided into eight groups based on the number of chlorine atoms, which vary from one to eight. The number and, to a lesser extent, the positions of the chlorine atoms within the chlorinated naphthalene molecule are the key determinants of the physical and chemical properties of the chlorinated naphthalenes congeners. Chlorinated naphthalenes with just a single chlorine atom are referred to as monochlorinated naphthalenes. “Polychlorinated naphthalenes” refers specifically to chlorinated naphthalenes with more than one chlorine atom (i.e. with two to eight chlorine atoms).
Beginning around 1910, chlorinated naphthalenes were produced commercially for a variety of uses such as chemical-resistant measurement fluids and instrument seals, heat exchange fluids, specialty solvents, for colour dispersions, as engine crankcase additives and as ingredients in motor tune-up compounds. The production of chlorinated naphthalenes in the United States of America ceased completely by 1980. (see footnote 3) Chlorinated naphthalenes are not currently in commercial use in Canada, the United States and many other countries belonging to the Organisation for Economic Co-operation and Development (OECD).
Although chlorinated naphthalenes are no longer in commercial use, they may be produced unintentionally as a by-product of various industrial processes involving chlorine, especially in the presence of heat. These processes include waste incineration, cement and magnesium production and the refining of metals. Other sources of chlorinated naphthalenes in the environment include products containing chlorinated naphthalenes that have been disposed of in landfill sites, and old industrial sites where chlorinated naphthalenes were used. Chlorinated naphthalenes can also be released to the atmosphere from domestic wood-burning, or naturally during forest fires. Chlorinated naphthalenes were likely never manufactured in Canada but were likely imported from manufacturers in the United States decades ago.
Data on environmental concentrations of chlorinated naphthalenes in Canada are limited, but these substances have been detected in several environmental samples in Canada (i.e. Arctic and urban air, water from Lake Ontario, fish and birds from the Great Lakes and environs, seals and whales from the Canadian Arctic, and Vancouver Island marmots). There is evidence of a downward trend in levels of chlorinated naphthalenes in Lake Ontario trout from 1979 to 2004. Internationally, dated sediment samples have also indicated downward trends in environmental levels of chlorinated naphthalenes. (see footnote 4) This trend is not surprising, given the declining use of chlorinated naphthalenes. However, the level of chlorinated naphthalenes in the Canadian environment appears to still be relatively high due in part to continued unintentional releases and to the substances’ resistance to degradation.
Ecological assessment conclusions
The number of chlorine atoms within the chlorinated naphthalene molecule impacts the physical and chemical properties of the chlorinated naphthalenes congeners and therefore the risk assessment conclusion.
Although monochlorinated naphthalenes may be harmful to aquatic organisms at relatively low concentrations, they have not been detected in the environment in Canada. Available evidence also indicates that monochlorinated naphthalenes are not bioaccumulative and are not persistent in the environment. Therefore, monochlorinated naphthalenes are not expected to pose a significant risk to the environment in Canada.
Toxicity data indicate that polychlorinated naphthalenes with two to five chlorine atoms may be harmful to aquatic organisms at relatively low concentrations. Also, polychlorinated naphthalenes with six to eight chlorine atoms were found to cause harmful effects in mammals after short-term exposure at relatively low doses. Scientific evidence also indicates that all polychlorinated naphthalenes are highly persistent in the environment and can accumulate in organisms.
Evidence that a substance is highly persistent and bioaccumulative, as defined in the Persistence and Bioaccumulation Regulations under CEPA 1999, taken together with potential for environmental release or formation and potential for toxicity in organisms, provides a significant indication that the substance may enter the environment under conditions that may have harmful long-term ecological effects. Substances that are persistent remain in the environment for a long time after being released, increasing the potential magnitude and duration of exposure. Substances that have long half-lives in air and water and partition into them in significant proportions have the potential to cause widespread contamination. Releases of small amounts of bioaccumulative substances may lead to high internal concentrations in exposed organisms. Highly bioaccumulative and persistent substances are of special concern, since they may biomagnify in food webs, resulting in very high internal exposures, especially to top predators.
Based on the information available, it is concluded that
- Polychlorinated naphthalenes are entering or may enter the environment in a quantity or concentration or under conditions that have or may have an immediate or long-term harmful effect on the environment or its biological diversity as defined under paragraph 64(a) of CEPA 1999; and
- Monochlorinated naphthalenes are not considered to enter the environment in a quantity or concentration or under conditions that have or may have an immediate or long-term harmful effect on the environment or its biological diversity or constitute or may constitute a danger to the environment on which life depends as set out in paragraphs 64(a) and (b) of CEPA 1999.
Polychlorinated naphthalenes are thus proposed for addition to Schedule 1 of CEPA 1999.
The presence of polychlorinated naphthalenes in the environment results primarily from human activity and they are persistent and bioaccumulative as per the criteria set out in the Persistence and Bioaccumulation Regulations, made under CEPA 1999. Therefore, they meet the criteria for implementation of virtual elimination of releases to the environment as defined under subsection 77(4).
The final ecological screening assessment report, the proposed risk management approach document and the complete responses to comments received on chlorinated naphthalenes (including polychlorinated naphthalenes) were published on July 2, 2011, and may be obtained from the Chemical Substances Web site at www.chemicalsubstances.gc.ca or from the Program Development and Engagement Division, Gatineau, Quebec K1A 0H3, 819-953-7155 (fax), email@example.com (email).
The following measures can be taken after an assessment is conducted under section 74 of CEPA 1999:
- adding the substance to the Priority Substances List for further assessment (when additional information is required to determine if a substance meets the criteria in section 64 or not);
- taking no further action in respect of the substance; or
- recommending that the substance be added to the List of Toxic Substances in Schedule 1, and, where applicable, the implementation of virtual elimination.
It has been concluded in the final ecological screening assessment report that polychlorinated naphthalenes are entering or may enter the environment in a quantity or concentration or under conditions that have or may have an immediate or long-term harmful effect on the environment or its biological diversity as defined under paragraph 64(a) of CEPA 1999. Adding these substances to Schedule 1, which will enable the development of regulations or other risk management instruments, is therefore the best option.
Benefits and costs
Adding these substances to Schedule 1 enables the Ministers to develop a proposed regulation or instrument to manage environmental risks posed by these substances. The Ministers will assess costs and benefits and consult with the public and other stakeholders during the development of these risk management proposals.
On July 18, 2009, the Ministers published a summary of the ecological assessment for chlorinated naphthalenes in the Canada Gazette, Part I, for a 60-day public comment period. The risk management scope document was also released on the same date, outlining the preliminary options being examined for the management of polychlorinated naphthalenes. Prior to this publication, Environment Canada and Health Canada informed the governments of the provinces and territories through the CEPA National Advisory Committee (NAC) of the release of the Screening Assessment report, the risk management scope document, and the public comment period mentioned above. No comments were received from CEPA NAC.
During the 60-day public comment period, a total of three submissions were received from industry associations. All comments were considered in developing the final assessment.
Comments were also received on the risk management scope document. They were considered when developing the proposed risk management approach document, which is also subject to a 60-day public comment period.
Below is a summary of comments received pertaining to the risk assessment conclusion, as well as responses to these comments. The complete responses to comments received may be obtained at the Web site, address or fax number or email address previously listed.
Comment: One chemical industry association observed that some literature indicates that generation of the chlorinated naphthalene compounds depends on the temperature. In a well-operated cement oven with operating temperatures from 900°C to 1 800°C, it is likely that the chlorinated naphthalene compounds that will be generated will then be destroyed within the cement oven itself, and only weakly chlorinated (and less persistent) compounds will be released by cement manufacturing operations, thus posing no risk to the environment or human health.
Response: Chlorinated naphthalenes are produced unintentionally as a by-product of many industrial processes involving chlorine atoms. The amount of chlorinated naphthalenes released into the environment from these sources has not been well characterized. The operating temperatures do not destroy all polychlorinated naphthalenes unintentionally formed during the manufacturing process, and polychlorinated naphthalenes can be emitted to the environment. Also, in the cement manufacturing process, fine particles are swept along to the facility’s particulate matter control train where the cement oven dust is captured in the dust collector. The cement oven dust can be problematic if it contains polychlorinated naphthalenes. The cement kiln dust may be managed by either introduction into cement products or it may be disposed at a provincially licensed landfill. Landfills accepting cement kiln dust, as part of their operating permits, are typically required to be lined and ground water in its vicinity to be monitored.
Comment: One chemical industry association mentioned that the true current balance of naturally occurring versus anthropogenic levels of chlorinated naphthalenes has not been clearly established, particularly, those quantities arising from non-industrial combustion sources are poorly characterized. Without this balance, for substances which were never manufactured in Canada and which are not currently in commercial use in the country, their designation for virtual elimination is of questionable value.
Response: Chlorinated naphthalenes were never manufactured in Canada and are not currently in commercial use. The presence of these substances results primarily from historical uses and past and current unintentional releases from industrial and non-industrial sources. Studies are under way to better characterize the incidental production of chlorinated naphthalenes, and possible management options will be based on results of these studies. Virtual elimination aims to reduce to non-measureable levels the releases of persistent, bioaccumulative and toxic substances, such as polychlorinated naphthalenes, resulting from human activity.
Comment: One chemical industry association noted that a recent study found an eightfold decline of polychlorinated naphthalenes in piscivorous fish in Lake Ontario which represents a valuable indication of a decline of polychlorinated naphthalenes levels in the Canadian environment and an indication that levels in Canadian aquatic wildlife have declined substantially. Such downward trends should reduce the “weight” of older monitoring data in the CEPA evaluation.
Response: Environment Canada emphasizes that the aforementioned study also found that concentrations of chlorinated naphthalenes in fish tissue are declining, but the decline is congener specific and the authors suggest that chlorinated naphthalene concentrations in lake trout may still be relatively high. A downward trend in ambient concentrations would not be surprising, given the declining uses of these substances. However, the level of chlorinated naphthalenes in the environment appears to still be relatively high — perhaps in part due to continued unintentional releases (e.g. from incineration which is a principal source of concern). Also, polychlorinated naphthalenes are persistent and bioaccumulative. A discussion of this issue has been added to the screening assessment report.
Implementation, enforcement and service standards
The proposed Order would add all polychlorinated naphthalenes to Schedule 1 of CEPA 1999, thereby allowing the Ministers to meet their obligation to publish proposed regulations or other management instruments no later than July 2, 2013, and finalize them no later than January 2, 2015. Developing an implementation plan, a compliance strategy or establishing service standards are not considered necessary without any specific risk management proposals. An appropriate assessment of implementation, compliance and enforcement will be undertaken during the development of a proposed regulation or control instrument(s) respecting preventive or control actions for polychlorinated naphthalenes.
Program Development and Engagement Division
Substances Management Information Line
Telephone: 1-800-567-1999 (toll free in Canada)
Telephone: 819-953-7156 (outside of Canada)
Risk Management Bureau
Notice is hereby given, pursuant to subsection 332(1) (see footnote a) of the Canadian Environmental Protection Act, 1999 (see footnote b), that the Governor in Council, on the recommendation of the Minister of the Environment and the Minister of Health, pursuant to subsection 90(1) of that Act, proposes to make the annexed Order Adding Toxic Substances to Schedule 1 to the Canadian Environmental Protection Act, 1999.
Any person may, within 60 days after the date of publication of this notice, file with the Minister of the Environment comments with respect to the proposed Order or a notice of objection requesting that a board of review be established under section 333 of that Act and stating the reasons for the objection. All comments and notices must cite the Canada Gazette, Part I, and the date of publication of this notice, and be sent by mail to the Executive Director, Program Development and Engagement Division, Department of the Environment, Gatineau, Quebec K1A 0H3, by fax to 819-953-7155 or by email to firstname.lastname@example.org.
A person who provides information to the Minister of the Environent may submit with the information a request for confidentiality under section 313 of that Act.
Ottawa, July 29, 2011
Assistant Clerk of the Privy Council
ORDER ADDING TOXIC SUBSTANCES TO SCHEDULE 1 TO THE CANADIAN ENVIRONMENTAL PROTECTION ACT, 1999
1. Schedule 1 to the Canadian Environmental Protection Act, 1999 (see footnote 5) is amended by adding the following:
Polychlorinated naphthalenes, which have the molecular formula C10H8–nCln in which “n” is greater than 1
COMING INTO FORCE
2. This Order comes into force on the day on which it is registered.
The Chemical Abstracts Service (CAS) Registry Number is the property of the American Chemical Society and any use or redistribution, except as required in supporting regulatory requirements and/or for reports to the Government when the information and the reports are required by law or administrative policy, is not permitted without the prior, written permission of the American Chemical Society.
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Harner, T., Kylin, H., Bidleman, T., Halsall, C., Strachan, W., Barrie, L., and Fellin, P. 1998. “Polychlorinated naphthalenes and coplanar polychlorinated biphenyls in Arctic air”. Environ Sci Technol. 32: 3257–3265.
Helm, P., Bidleman, T., Sternand, G., and Koczanski, K. 2002. “Polychlorinated naphthalenes and coplanar polychlorinated biphenyls in beluga whale (Delphinapterus leucas) and ringed seal (Phoca hispida) from the eastern Canadian Arctic”. Environmental Pollution. 119: 69–78.
Helm, P. A., Bidleman, T. F., Li, H. H., and Fellin, P. 2004. “Seasonal and spatial variation of polychlorinated naphthalenes and non-/mono-ortho-substituted polychlorinated biphenyls in arctic air”. Environ Sci Technol. 38(21): 5514–5521.
Helm, P. A., and Bidleman, T. F. 2005. “Gas–particle partitioning of polychlor inated naphthalenes and non- and mono-ortho-substituted polychlorinated biphenyls in arctic air”. Science of the Total Environment. 342(1): 161–173.
International Programme on Chemical Safety (IPCS). 2001. Concise International Chemical Assessment Document (CICAD) No. 34, Chlorinated Naphthalenes. World Health Organization, Geneva.
Gewurtz, S. B., Lega, R., Crozier, P. W., Whittle, D. M., Fayez, L., Reiner, E. J., Helm, P. A., Marvin, C. H. and Tomy, G. T. 2009. “Factors influencing trends of polychlorinated naphthalenes and other dioxin-like compounds in Lake Trout (Salvelinus Namaycush) from Lake Ontario, North America (1979-2004)”. Environmental Toxicology and Chemistry 28: 921–930.
S.C. 1999, c. 33
S.C. 2004, c. 15, s. 31
S.C. 1999, c. 33