ARCHIVED — DEPARTMENT OF HEALTH

Warning This Web page has been archived on the Web.

Archived Content

Information identified as archived is provided for reference, research or recordkeeping purposes. It is not subject to the Government of Canada Web Standards and has not been altered or updated since it was archived. Please contact us to request a format other than those available.

Vol. 143, No. 5 — January 31, 2009

CANADIAN ENVIRONMENTAL PROTECTION ACT, 1999

Publication of Final Decision on the
Screening Assessment of Substances — Batch 2

CAS No. 732-26-3
CAS No. 62-56-6
CAS No. 78-79-5
CAS No. 106-89-8
CAS No. 1344-37-2
CAS No. 12656-85-8
CAS No. 108-05-4
CAS No. 2778-42-9
CAS No. 4474-24-2
CAS No. 15086-94-9
CAS No. 125351-99-7
CAS No. 70161-19-2
CAS No. 83006-67-1
CAS No. 556-67-2
CAS No. 541-02-6
CAS No. 540-97-6


Publication of final decision on the screening assessment of a substance — Phenol, 2,4,6-tris(1,1-dimethylethyl)- (2,4,6-tri-tert-butylphenol), CAS No. 732-26-3 — specified on the Domestic Substances List [subsection 77(6) of the Canadian Environmental Protection Act, 1999]

Whereas 2,4,6-tri-tert-butylphenol is a substance on the Domestic Substances List identified under subsection 73(1) of the Canadian Environmental Protection Act, 1999;

Whereas a summary of the final Screening Assessment Report conducted on 2,4,6-tri-tert-butylphenol pursuant to section 74 of the Act is annexed hereby;

Whereas 2,4,6-tri-tert-butylphenol meets one or more of the criteria set out in section 64 of the Act; and

Whereas the Ministers are satisfied that the criteria set out under subsection 77(4) of the Act are met,

Notice therefore is hereby given that the Ministers of the Environment and of Health intend to recommend to Her Excellency the Governor in Council that 2,4,6-tri-tert-butylphenol be added to Schedule 1 to the Act.

Notice therefore is further given that the Ministers of the Environment and of Health propose the implementation of virtual elimination of 2,4,6-tri-tert-butylphenol under subsection 65(3) of the Act.

Notice is furthermore given that the Ministers of the Environment and of Health have released a proposed risk management approach document, for a public comment period of 60 days, to continue discussions with stakeholders regarding the risk management actions for this substance.

Public comment period on the proposed risk management approach document

Any person may, within 60 days after publication of the proposed risk management approach document, file with the Minister of the Environment written comments on the risk management approach document. More information regarding the proposed risk management approach may be obtained from the Government of Canada’s Chemical Substances Web site (www. chemicalsubstances.gc.ca). All comments must cite the Canada Gazette, Part I, and the date of publication of this notice and be sent to the Executive Director, Existing Substances Division, Gatineau, Quebec K1A 0H3, 1-800-410-4314 or 819-953-4936 (fax), or by email to Existing.Substances.Existantes@ec.gc.ca.

In accordance with section 313 of the Canadian Environmental Protection Act, 1999, any person who provides information in response to this notice may submit with the information a request that it be treated as confidential.

JIM PRENTICE
Minister of the Environment

LEONA AGLUKKAQ
Minister of Health

ANNEX

Summary of the Screening Assessment Report of Phenol, 2,4,6-tris(1,1-dimethylethyl)-

Pursuant to section 74 of the Canadian Environmental Protection Act, 1999 (CEPA 1999), the Ministers of the Environment and of Health have conducted a screening assessment on Phenol, 2,4,6-tris(1,1-dimethylethyl)- (2,4,6-tri-tert-butylphenol), Chemical Abstracts Service Registry No. 732-26-3. This substance was identified as a high priority for screening assessment and included in the Ministerial Challenge because it was found to meet the ecological categorization criteria for persistence, bioaccumulation potential and inherent toxicity to non-human organisms and is known to be in commerce in Canada.

The substance 2,4,6-tri-tert-butylphenol was not considered to be a high priority for assessment of potential risks to human health, based upon application of the simple exposure and hazard tools developed by Health Canada for categorization of substances on the Domestic Substances List. Therefore, this assessment focuses on information relevant to the evaluation of ecological risks.

The substance 2,4,6-tri-tert-butylphenol is an antioxidant which can be used as a fuel, oil, gasoline or lubricant additive. The only use in Canada is as a fuel additive. The substance is not naturally produced in the environment. Although it was not reported to be manufactured in Canada above the reporting threshold, total imports were reported to be in a quantity between 10 000 and 100 000 kg in the year 2000. Voluntary submissions received in 2007 reported a quantity between 1 000 and 10 000 kg of this substance being imported into Canada in the calendar year 2006. This substance was also reported to be used below the reporting threshold. Quantities of 2,4,6-tri-tert-butylphenol imported into Canada, along with its use as a fuel additive, indicate that this chemical may potentially be released into the Canadian environment. Although the information gathered to date indicates that the only current use of the substance is as a fuel additive, 2,4,6-tri-tert-butylphenol has been used in the past in Canada as a lubricant additive, and this is a recognized use for the substance elsewhere. As a result, the calculations used to make this assumption for release include a minor use of the substance as a lubricant additive.

Based on certain assumptions and reported use patterns, most of 2,4,6-tri-tert-butylphenol may be destroyed through the combustion of fuel/oil. Small proportions are estimated to be released to water (0.3%), air (1.6%) and soil (0.1%). There is also a proportion estimated to be transferred to waste disposal sites (4.8%). Given this substance’s physical and chemical characteristics, it is expected to strongly adsorb to soil and sediment. This substance is not likely to be metabolized (given its highly branched chemical structure) and will have a tendency to partition to lipids (fat) of organisms because of its hydrophobic nature.

Based on its physical and chemical properties, 2,4,6-tri-tert-butylphenol does not degrade quickly in the environment; it is expected to be persistent in water, soil and sediments. Empirical and modelled data indicate that this substance also has the potential to accumulate in organisms and may biomagnify in trophic food chains. The substance has been determined to meet the persistence and bioaccumulation criteria as set out in the Persistence and Bioaccumulation Regulations. In addition, acute aquatic toxicity values suggest that the substance is highly hazardous to aquatic organisms.

Given that long-term risks associated with persistent and bioaccumulative substances cannot at present be reliably predicted, quantitative risk estimates have limited relevance. A conservative response to uncertainty is justified based upon the bioaccumulative and persistent nature of this substance.

This substance will be included in the upcoming Domestic Substances List inventory update initiative. In addition and where relevant, research and monitoring will support verification of assumptions used during the screening assessment and, where appropriate, the performance of potential control measures identified during the risk management phase.

Conclusion

Based on the information available, it is concluded that 2,4,6-tris(1,1-dimethylethyl)- meets one or more of the criteria set out in section 64 of CEPA 1999. The substance 2,4,6-tris(1,1-dimethylethyl)- is persistent and bioaccumulative in accordance with the Persistence and Bioaccumulation Regulations, its presence in the environment results primarily from human activity, and it is not a naturally occurring radionuclide or a naturally occurring inorganic substance.

The final Screening Assessment Report as well as the proposed risk management approach document for this substance are available on the Government of Canada’s Chemical Substances Web site (www.chemicalsubstances.gc.ca).

Publication of final decision on the screening assessment of a substance — Thiourea, CAS No. 62-56-6 — specified on the Domestic Substances List [subsection 77(6) of the Canadian Environmental Protection Act, 1999]

Whereas thiourea is a substance on the Domestic Substances List identified under subsection 73(1) of the Canadian Environmental Protection Act, 1999;

Whereas a summary of the final Screening Assessment Report conducted on thiourea pursuant to section 74 of the Act is annexed hereby; and

Whereas thiourea meets one or more of the criteria set out in section 64 of the Act,

Notice therefore is hereby given that the Ministers of the Environment and of Health intend to recommend to Her Excellency the Governor in Council that thiourea be added to Schedule 1 to the Act.

Notice is furthermore given that the Ministers of the Environment and of Health have released a proposed risk management approach document, for a public comment period of 60 days, to continue discussions with stakeholders regarding the risk management actions for this substance.

Public comment period on the proposed risk management approach document

Any person may, within 60 days after publication of the proposed risk management approach document, file with the Minister of the Environment written comments on the risk management approach document. More information regarding the proposed risk management approach may be obtained from the Government of Canada’s Chemical Substances Web site (www.chemicalsubstances.gc.ca). All comments must cite the Canada Gazette, Part I, and the date of publication of this notice and be sent to the Executive Director, Existing Substances Division, Gatineau, Quebec K1A 0H3, 1-800-410-4314 or 819-953-4936 (fax), or by email to Existing.Substances.Existantes@ec.gc.ca.

In accordance with section 313 of the Canadian Environmental Protection Act, 1999, any person who provides information in response to this notice may submit with the information a request that it be treated as confidential.

JIM PRENTICE
Minister of the Environment

LEONA AGLUKKAQ
Minister of Health

ANNEX

Summary of the Screening Assessment Report of Thiourea

Pursuant to section 74 of the Canadian Environmental Protection Act, 1999 (CEPA 1999), the Ministers of the Environment and of Health have conducted a screening assessment of thiourea, Chemical Abstracts Service Registry No. 62-56-6. This substance was identified in the categorization of the Domestic Substances List as a high priority for action under the Ministerial Challenge. Thiourea was identified as a high priority as it was considered to pose greatest potential for exposure to individuals in Canada and had been classified by other agencies on the basis of carcinogenicity and reproductive/developmental toxicity. The substance did meet the ecological categorization criteria for persistence in water, soil and sediment but it did not meet the criterion for bioaccumulation potential or inherent toxicity to aquatic organisms. Therefore, the focus of this assessment of thiourea relates to human health risks.

According to information reported under section 71 of CEPA 1999, thiourea was imported into Canada in 2006 in a quantity ranging between 10 000 and 100 000 kg. Thiourea is used in metal finishing solutions and in etching treatments used for printed circuit boards, and as a reducing agent in the production of thiourea dioxide, a chemical intermediate, a reactant in the copper refinery industry and a rust inhibitor. In addition, thiourea may be included in silver polish, tarnish removers, metal cleaners, black and white photographic chemicals, blueprint papers and pharmaceutical synthesis.

Exposure to thiourea via the general environment is considered to be negligible; therefore, the predominant source of general population exposure to thiourea is expected to be as a result of its presence in consumer products.

Based principally on the weight-of-evidence-based assessments of international or national agencies, a critical effect for the characterization of risk to human health for thiourea is carcinogenicity. The substance induced tumours at multiple sites in male and female rats and in the mammary gland in mice. Although thiourea appears to be only weakly genotoxic, the mode of induction of tumours has not been fully elucidated; therefore, it cannot be precluded that the tumours observed in experimental animals resulted from direct interaction with genetic material. In addition, the margins between upper-bounding estimates of exposure through inhalation and through dermal routes during use of consumer products containing thiourea and critical effect levels for non-cancer effects in short-term and reproductive toxicity studies may not be adequate to account for the uncertainties in the databases on exposure and effects, particularly in view of the uncertainties in the mode of induction of tumours.

On the basis of the carcinogenicity of thiourea, for which there may be a probability of harm at any level of exposure, as well as the potential inadequacy of the margins of exposure for non-cancer effects, it is concluded that thiourea is a substance that may be entering the environment in a quantity or concentration or under conditions that constitute or may constitute a danger in Canada to human life or health.

On the basis of ecological hazard and reported releases of thiourea, it is concluded that this substance is not entering 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 that constitute or may constitute a danger to the environment on which life depends. Although thiourea does meet criteria for persistence, it does not meet the criterion for bioaccumulation potential as set out in the Persistence and Bioaccumulation Regulations.

This substance will be included in the upcoming Domestic Substances List inventory update initiative. In addition and where relevant, research and monitoring will support verification of assumptions used during the screening assessment and, where appropriate, the performance of potential control measures identified during the risk management phase.

Conclusion

Based on the information available, it is concluded that thiourea meets one or more of the criteria set out in section 64 of CEPA 1999.

The final Screening Assessment Report as well as the proposed risk management approach document for this substance are available on the Government of Canada’s Chemical Substances Web site (www.chemicalsubstances.gc.ca).

Publication of final decision on the screening assessment of a substance — 1,3-Butadiene, 2-methyl- (isoprene) CAS No. 78-79-5 — specified on the Domestic Substances List [subsection 77(6) of the Canadian Environmental Protection Act, 1999]

Whereas isoprene is a substance on the Domestic Substances List identified under subsection 73(1) of the Canadian Environmental Protection Act, 1999;

Whereas a summary of the final Screening Assessment Report conducted on isoprene pursuant to section 74 of the Act is annexed hereby; and

Whereas isoprene meets one or more of the criteria set out in section 64 of the Act,

Notice therefore is hereby given that the Ministers of the Environment and of Health intend to recommend to Her Excellency the Governor in Council that isoprene be added to Schedule 1 to the Act.

Notice is furthermore given that the Ministers of the Environment and of Health have released a proposed risk management approach document, for a public comment period of 60 days, to continue discussions with stakeholders regarding the risk management actions for this substance.

Public comment period on the proposed risk management approach document

Any person may, within 60 days after publication of the proposed risk management approach document, file with the Minister of the Environment written comments on the risk management approach document. More information regarding the proposed risk management approach may be obtained from the Government of Canada’s Chemical Substances Web site www.chemicalsubstances.gc.ca. All comments must cite the Canada Gazette, Part I, and the date of publication of this notice and be sent to the Executive Director, Existing Substances Division, Gatineau, Quebec K1A 0H3, 1-800-410-4314 or 819-953-4936 (fax), or by email to Existing.Substances.Existantes@ec.gc.ca.

In accordance with section 313 of the Canadian Environmental Protection Act, 1999, any person who provides information in response to this notice may submit with the information a request that it be treated as confidential.

JIM PRENTICE
Minister of the Environment

LEONA AGLUKKAQ
Minister of Health

ANNEX

Summary of the Screening Assessment Report of 1,3-Butadiene, 2-methyl-

Pursuant to section 74 of the Canadian Environmental Protection Act, 1999 (CEPA 1999), the Ministers of the Environment and of Health have conducted a screening assessment of 1,3-Butadiene, 2-methyl- (isoprene), Chemical Abstracts Service Registry No. 78-79-5. This substance was identified in the categorization of the Domestic Substances List as a high priority for action under the Ministerial Challenge. Isoprene was identified as a high priority as it was considered to pose greatest potential for exposure to individuals in Canada and had been classified by other agencies on the basis of carcinogenicity and mutagenicity. The substance did not meet the criteria for persistence, bioaccumulation or inherent toxicity to aquatic organisms. Therefore, the focus of this assessment on isoprene relates to human health aspects.

Under information reported pursuant to section 71 of CEPA 1999, the total quantity of isoprene manufactured in Canada in 2006 exceeded 10 000 000 kg and the total quantity imported ranged from 1 000 000 to 10 000 000 kg. This substance is used mainly as a monomer in the production of polyisoprene, butyl rubber and styrene-isoprene-styrene (SIS) rubber. Polyisoprene is subsequently used in the production of vehicle tires and a wide variety of products including paint resins, footwear, adhesives and molded goods. Butyl rubber is typically used in the manufacture of inner tubes, while SIS rubber is used in pressure sensitive adhesives. Isoprene is also used in the formulation of viscosity improvers for motor oil and in the production of agrochemicals, pharmaceuticals and other substances.

Isoprene is emitted into the environment from both natural and anthropogenic sources, and the principal route of exposure for the general population will likely be through inhalation of ambient and indoor air. Off-gassing of isoprene from consumer products manufactured from polyisoprene may also contribute to the levels of the substance in indoor air.

Based principally on the weight-of-evidence-based assessments of several international and national agencies, a critical effect for the characterization of risk to human health is carcinogenicity, based on observation of tumours at multiple organ sites in rats and mice. Isoprene was also genotoxic in several in vivo assays. Therefore, although the mode of action has not been fully elucidated, it cannot be precluded that tumours observed in experimental animals resulted from direct interaction with genetic material.

On the basis of carcinogenicity, for which there may be a probability of harm at any level of exposure, as well as the potential inadequacy of the margin between concentrations of isoprene in indoor air and levels associated with non-cancer effects in the thymus in a subchronic study, it is concluded that isoprene be considered as a substance which may be entering the environment in a quantity or concentration or under conditions that constitute or may constitute a danger in Canada to human life or health.

On the basis of low ecological hazard and reported releases of isoprene, it is concluded that this substance is not entering 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 that constitute or may constitute a danger to the environment on which life depends. As set out in the Persistence and Bioaccumulation Regulations, isoprene does not meet the criteria for persistence in air, water, soil or sediment, nor does it meet the criteria for bioaccumulation potential.

This substance will be included in the upcoming Domestic Substances List inventory update initiative. In addition and where relevant, research and monitoring will support verification of assumptions used during the screening assessment and, where appropriate, the performance of potential control measures identified during the risk management phase.

Conclusion

Based on the information available, it is concluded that isoprene meets one or more of the criteria set out in section 64 of CEPA 1999.

The final Screening Assessment Report as well as the proposed risk management approach document for this substance are available on the Government of Canada’s Chemical Substances Web site (www.chemicalsubstances.gc.ca).

Publication of final decision on the screening assessment of a substance — Oxirane, (chloromethyl)- (epichlorohydrin) CAS No. 106-89-8 — specified on the Domestic Substances List [subsection 77(6) of the Canadian Environmental Protection Act, 1999]

Whereas epichlorohydrin is a substance on the Domestic Substances List identified under subsection 73(1) of the Canadian Environmental Protection Act, 1999;

Whereas a summary of the final Screening Assessment Report conducted on epichlorohydrin pursuant to section 74 of the Act is annexed hereby; and

Whereas epichlorohydrin meets one or more of the criteria set out in section 64 of the Act,

Notice therefore is hereby given that the Ministers of the Environment and of Health intend to recommend to Her Excellency the Governor in Council that epichlorohydrin be added to Schedule 1 to the Act.

Notice is furthermore given that the Ministers of the Environment and of Health have released a proposed risk management approach document, for a public comment period of 60 days, to continue discussions with stakeholders regarding the risk management actions for this substance.

Public comment period on the proposed risk management approach document

Any person may, within 60 days after publication of the proposed risk management approach document, file with the Minister of the Environment written comments on the risk management approach document. More information regarding the proposed risk management approach may be obtained from the Government of Canada’s Chemical Substances Web site (www.chemicalsubstances.gc.ca). All comments must cite the Canada Gazette, Part I, and the date of publication of this notice and be sent to the Executive Director, Existing Substances Division, Gatineau, Quebec K1A 0H3, 1-800-410-4314 or 819-953-4936 (fax), or by email to Existing.Substances.Existantes@ec.gc.ca.

In accordance with section 313 of the Canadian Environmental Protection Act, 1999, any person who provides information in response to this notice may submit with the information a request that it be treated as confidential.

JIM PRENTICE
Minister of the Environment

LEONA AGLUKKAQ
Minister of Health

ANNEX

Summary of the Screening Assessment Report of Oxirane, (chloromethyl)-

The Ministers of the Environment and of Health have conducted a screening assessment of Oxirane, (chloromethyl)-, Chemical Abstracts Service Registry No. 106-89-8 (epichlorohydrin), a substance identified in the categorization of the DomesticSubstancesList as a high priority for action under the Ministerial Challenge. Epichlorohydrin was identified as a high priority as it was considered to pose greatest potential for exposure to individuals in Canada and had been classified by other agencies on the basis of carcinogenicity. The substance did not meet the ecological categorization criteria for persistence, bioaccumulation or inherent toxicity to aquatic organisms. Therefore, the focus of this assessment on epichlorohydrin relates to human health aspects.

Under information reported pursuant to section 71 of the Canadian Environmental Protection Act, 1999 (CEPA 1999), in 2006 epichlorohydrin was not manufactured in or imported into Canada by any company above the 100 kg threshold. It is likely that epichlorohydrin is being imported in very small amounts as residual monomer in products containing epoxy resin or other resins made using epichlorohydrin. Direct use of epichlorohydrin by consumers is not expected. The principal use of epichlorohydrin is in the production of epoxy and phenoxy resins, which are primarily used in protective coatings and thermoplastic polymers. It may also be used for the production of synthetic glycerol, and in the chemical synthesis of pharmaceutical products, polyols, and surface active agents for washing products and toiletries. Polymers made with epichlorohydrin are used as additives in papermaking, as cross-linking agents for starches, and as anion-exchange resins and flocculants used in treating drinking and wastewater.

In Canada, since epichlorohydrin is present only as a residual, environmental and consumer product exposures are expected to be low to negligible. No empirical data were identified regarding measured concentrations of epichlorohydrin in environmental media (i.e. air, water, soil and food) in Canada. Based on its possible uses, oral exposure to epichlorohydrin via food and/or drinking water may occur at low levels for the general population of Canada. Contributions from ambient air and soil are expected to be negligible due to the lack of manufacture in and/or import of this substance into Canada. There is also the possibility of low level exposure to epichlorohydrin via inhalation during the use of consumer products that contain residual amounts of epichlorohydrin monomer.

Based principally on the weight-of-evidence-based assessments of several international and national agencies, a critical effect for the characterization of risk to human health is carcinogenicity, based on observation of tumours in rats and tumour initiation in mice. Epichlorohydrin was genotoxic in a wide range of in vitro and in vivo experimental systems, as well as in investigations of occupationally exposed humans. Therefore, although the mode of action has not been fully elucidated, it cannot be precluded that tumours observed in experimental animals resulted from direct interaction with genetic material.

On the basis of carcinogenicity, for which there may be a probability of harm at any level of exposure, it is concluded that epichlorohydrin is a substance which may be entering the environment in a quantity or concentration or under conditions that constitute or may constitute a danger in Canada to human life or health.

On the basis of moderate ecological hazard and low reported releases of epichlorohydrin, it is concluded that this substance is not entering 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 that constitute or may constitute a danger to the environment on which life depends. Although epichlorohydrin does meet the criterion for persistence, it does not meet the criterion for bioaccumulation potential as set out in the Persistence and Bioaccumulation Regulations.

The substance will be included in the upcoming Domestic Substance List inventory update initiative. In addition and where relevant, research and monitoring will support verification of assumptions used during the screening assessment and, where appropriate, the performance of potential control measures identified during the risk management phase.

Conclusion

Based on the information available, it is concluded that epichlorohydrin meets one or more of the criteria set out in section 64 of CEPA 1999.

The final Screening Assessment Report as well as the proposed risk management approach document for this substance are available on the Government of Canada’s Chemical Substances Web site (www.chemicalsubstances.gc.ca).

Publication of final decision on the screening assessment of a substance — C.I. Pigment Yellow 34, CAS No. 1344-37-2 — specified on the Domestic Substances List [subsection 77(6) of the Canadian Environmental Protection Act, 1999]

Whereas C.I. Pigment Yellow 34 is a substance on the Domestic Substances List identified under subsection 73(1) of the Canadian Environmental Protection Act, 1999;

Whereas a summary of the final Screening Assessment Report conducted on C.I. Pigment Yellow 34 pursuant to section 74 of the Act is annexed hereby; and

Whereas C.I. Pigment Yellow 34 meets one or more of the criteria set out in section 64 of the Act,

Notice therefore is hereby given that the Ministers of the Environment and of Health intend to recommend to Her Excellency the Governor in Council that C.I. Pigment Yellow 34 be added to Schedule 1 to the Act.

Notice is furthermore given that the Ministers of the Environment and of Health have released a proposed risk management approach document, for a public comment period of 60 days, to continue discussions with stakeholders regarding the risk management actions for this substance.

Public comment period on the proposed risk management approach document

Any person may, within 60 days after publication of the proposed risk management approach document, file with the Minister of the Environment written comments on the risk management approach document. More information regarding the proposed risk management approach may be obtained from the Government of Canada’s Chemical Substances Web site (www.chemicalsubstances.gc.ca). All comments must cite the Canada Gazette, Part I, and the date of publication of this notice and be sent to the Executive Director, Existing Substances Division, Gatineau, Quebec K1A 0H3, 1-800-410-4314 or 819-953-4936 (fax), or by email to Existing.Substances.Existantes@ec.gc.ca.

In accordance with section 313 of the Canadian Environmental Protection Act, 1999, any person who provides information in response to this notice may submit with the information a request that it be treated as confidential.

JIM PRENTICE
Minister of the Environment

LEONA AGLUKKAQ
Minister of Health

ANNEX

Summary of the Screening Assessment Report of C.I. Pigment Yellow 34

Pursuant to section 74 of the Canadian Environmental Protection Act, 1999 (CEPA 1999), the Ministers of the Environment and of Health have conducted a screening assessment of C.I. Pigment Yellow 34, Chemical Abstracts Service Registry No. 1344-37-2. The substance C.I. Pigment Yellow 34 was identified in the categorization of the Domestic Substances List as a high priority for action under the Ministerial Challenge. The substance was identified as a high priority because it was considered to pose greatest potential for exposure to individuals in Canada and had been classified by other agencies on the basis of carcinogenicity, reproductive toxicity and developmental toxicity. The substance also met the ecological categorization criteria for persistence and inherent toxicity to aquatic organisms. Therefore, this assessment of C.I. Pigment Yellow 34 focuses on information relevant to the evaluation of both human health and ecological risks.

In response to a notice issued under section 71 of CEPA 1999, in 2006 C.I. Pigment Yellow 34 was reported to be manufactured in and imported into Canada. After exports, the amount remaining for use in this country ranged between 1 000 000 and 10 000 000 kg. It is primarily used for plastic formulation for commercial applications and export; commercial, non-consumer paints and coatings; and commercial printing inks or coatings used for plastics and certain outdoor applications such as commercial identification decals.

There were no empirical data identified regarding measured concentrations of C.I. Pigment Yellow 34 in environmental media (i.e. air, water, soil and food) in Canada. Given the physical and chemical properties and sources of this substance, exposure to C.I. Pigment Yellow 34 is expected to be negligible via drinking water, ambient air or consumer products. Exposure to the general population in Canada is expected to be predominantly from soils, although these exposures are expected to be low due to the primarily commercial use of the substance, very limited industrial releases, and the encapsulation and incorporation of the substance into a solid matrix. However, these exposures could not be quantified due to lack of measured concentrations.

The substance C.I. Pigment Yellow 34 is considered persistent because it contains metal ions, lead (Pb2+) and the chromate (CrO42-) ions, which are considered to be infinitely persistent. Therefore, C.I. Pigment Yellow 34 meets the persistence criteria as set out in the Persistence and Bioaccumulation Regulations. The current state of the science does not allow for the unambiguous interpretation of the bioaccumulation potential of metal-containing inorganic substances such as C.I. Pigment Yellow 34. Experimental toxicity studies suggest that the substance is not hazardous to aquatic organisms at a loading rate (100 mg/L) that is considered to represent a reasonable environmental worst-case scenario. Additionally, considering its low solubility, it is unlikely that organisms associated with other compartments would be harmed by exposure to this substance.

Based principally on the weight-of-evidence-based classification of C.I. Pigment Yellow 34 by the European Commission, and the assessment of hexavalent chromium and inorganic lead compounds by several national and international agencies, a critical effect for the characterization of risk to human health is carcinogenicity. The substance C.I. Pigment Yellow 34, together with lead chromate and C.I. Pigment Red 104, was carcinogenic in rats after subcutaneous and intramuscular administration and these animal studies are supported by epidemiological studies, which indicate an increased frequency of lung cancer in chromate pigment production workers. As well, C.I. Pigment Yellow 34 or its principal components were genotoxic in a limited number of in vitro and in vivo experimental systems.

On the basis of the carcinogenicity of C.I. Pigment Yellow 34, for which there may be a probability of harm at any level of exposure, it is concluded that C.I. Pigment Yellow 34 is a substance that may be entering the environment in a quantity or concentration or under conditions that constitute or may constitute a danger in Canada to human life or health.

On the basis of ecological hazard and reported releases of C.I. Pigment Yellow 34, it is concluded that this substance is not entering 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 that constitute or may constitute a danger to the environment on which life depends.

This substance will be included in the upcoming Domestic Substances List inventory update initiative. In addition and where relevant, research and monitoring will support verification of assumptions used during the screening assessment and, where appropriate, the performance of potential control measures identified during the risk management phase.

Conclusion

Based on the information available, it is concluded that C.I. Pigment Yellow 34 meets one or more of the criteria set out in section 64 of CEPA 1999.

The final Screening Assessment Report as well as the proposed risk management approach document for this substance are available on the Government of Canada’s Chemical Substances Web site (www.chemicalsubstances.gc.ca).

Publication of final decision on the screening assessment of a substance — C.I. Pigment Red 104, CAS No. 12656-85-8 — specified on the Domestic Substances List [subsection 77(6) of the Canadian Environmental Protection Act, 1999]

Whereas C.I. Pigment Red 104 is a substance on the Domestic Substances List identified under subsection 73(1) of the Canadian Environmental Protection Act, 1999;

Whereas a summary of the final Screening Assessment Report conducted on C.I. Pigment Red 104 pursuant to section 74 of the Act is annexed hereby; and

Whereas C.I. Pigment Red 104 meets one or more of the criteria set out in section 64 of the Act,

Notice therefore is hereby given that the Ministers of the Environment and of Health intend to recommend to Her Excellency the Governor in Council that C.I. Pigment Red 104 be added to Schedule 1 to the Act.

Notice is furthermore given that the Ministers of the Environment and of Health have released a proposed risk management approach document, for a public comment period of 60 days, to continue discussions with stakeholders regarding the risk management actions for this substance.

Public comment period on the proposed risk management approach document

Any person may, within 60 days after publication of the proposed risk management approach document, file with the Minister of the Environment written comments on the risk management approach document. More information regarding the proposed risk management approach may be obtained from the Government of Canada’s Chemical Substances Web site (www.chemicalsubstances.gc.ca). All comments must cite the Canada Gazette, Part I, and the date of publication of this notice and be sent to the Executive Director, Existing Substances Division, Gatineau, Quebec K1A 0H3, 1-800-410-4314 or 819-953-4936 (fax), or by email to Existing.Substances.Existantes@ec.gc.ca.

In accordance with section 313 of the Canadian Environmental Protection Act, 1999, any person who provides information in response to this notice may submit with the information a request that it be treated as confidential.

JIM PRENTICE
Minister of the Environment

LEONA AGLUKKAQ
Minister of Health

ANNEX

Summary of the Screening Assessment Report of C.I. Pigment Red 104

Pursuant to section 74 of the Canadian Environmental Protection Act, 1999 (CEPA 1999), the Ministers of the Environment and of Health have conducted a screening assessment of C.I. Pigment Red 104, Chemical Abstracts Service Registry No. 12656-85-8. The substance C.I. Pigment Red 104 was identified in the categorization of the DomesticSubstancesList as a high priority for action under the Ministerial Challenge. The substance was identified as a high priority because it was considered to pose greatest potential for exposure to individuals in Canada and had been classified by other agencies on the basis of carcinogenicity, reproductive toxicity and developmental toxicity. The substance also met the ecological categorization criteria for persistence and inherent toxicity to aquatic organisms. Therefore, this assessment of C.I. Pigment Red 104 focuses on information relevant to the evaluation of both human health and ecological risks.

In response to a notice issued under section 71 of CEPA 1999, in 2006 C.I. Pigment Red 104 was reported to be manufactured in and imported into Canada. After exports, the amount remaining for use in this country ranged between 100 000 and 1 000 000 kg. It is primarily used for plastic formulation for commercial applications and export; commercial, non-consumer paints and coatings; and commercial printing inks or coatings used for plastics and certain outdoor applications such as commercial identification decals.

There were no empirical data identified regarding measured concentrations of C.I. Pigment Red 104 in environmental media (i.e. air, water, soil and food) in Canada. Given the physical and chemical properties and sources of this substance, exposure to C.I. Pigment Red 104 is expected to be negligible via drinking water, ambient air or consumer products. Exposure to the general population in Canada is expected to be predominantly from soils, although these exposures are expected to be low due to the primarily commercial use of the substance, very limited industrial releases and the encapsulation and incorporation of the substance into a solid matrix. However, these exposures could not be quantified due to lack of measured concentrations.

The substance C.I. Pigment Red 104 is considered persistent because it contains metal ions, lead (Pb2+) and the chromate (CrO42-) ions, which are considered to be infinitely persistent. Therefore, C.I. Pigment Red 104 meets the persistence criteria as set out in the Persistence and Bioaccumulation Regulations. The current state of science does not allow for the unambiguous interpretation of the bioaccumulation potential of metal-containing inorganic substances such as C.I. Pigment Red 104. Experimental toxicity studies conducted with its analogue, C.I. Pigment Red 34, suggest that C.I. Pigment Red 104 is not hazardous to aquatic organisms at a loading rate (100 mg/L) that is considered to represent a reasonable environmental worst-case scenario. Additionally, considering the low solubility of C.I. Pigment Red 104 and its analogue, C.I. Pigment Yellow 34, it is unlikely that organisms associated with other compartments would be harmed by exposure to C.I. Pigment Red 104 as well.

Based principally on the weight-of-evidence classification of C.I. Pigment Red 104 by the European Commission and the assessment of hexavalent chromium and inorganic lead compounds by several national and international agencies, a critical effect for the characterization of risk to human health is carcinogenicity. The substance C.I. Pigment Red 104, together with lead chromate and C.I. Pigment Yellow 34, was carcinogenic in rats after subcutaneous and intramuscular administration and these animal studies are supported by epidemiological studies that indicate an increased frequency of lung cancer in chromate pigment production workers. As well, C.I. Pigment Red 104 or its principal components were genotoxic in a limited number of in vitro and in vivo experimental systems.

On the basis of the carcinogenicity of C.I. Pigment Red 104, for which there may be a probability of harm at any level of exposure, it is concluded that C.I. Pigment Red 104 is a substance that may be entering the environment in a quantity or concentration or under conditions that constitute or may constitute a danger in Canada to human life or health.

On the basis of the low ecological hazard and reported releases of C.I. Pigment Red 104, it is concluded that this substance is not entering 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 that constitute or may constitute a danger to the environment on which life depends. The substance C.I. Pigment Red 104 meets the criteria for persistence as set out in the Persistence and Bioaccumulation Regulations.

This substance will be included in the upcoming Domestic Substance List inventory update initiative. In addition and where relevant, research and monitoring will support verification of assumptions used during the screening assessment and, where appropriate, the performance of potential control measures identified during the risk management phase.

Conclusion

Based on the information available, it is concluded that C.I. Pigment Red 104 meets one or more of the criteria set out in section 64 of CEPA 1999.

The final Screening Assessment Report as well as the proposed risk management approach document for this substance are available on the Government of Canada’s Chemical Substances Web site (www.chemicalsubstances.gc.ca).

Publication of final decision on the screening assessment of a substance — Acetic acid ethenyl ester (vinyl acetate monomer), CAS No. 108-05-4 — specified on the Domestic Substances List [subsection 77(6) of the Canadian Environmental Protection Act, 1999]

Whereas vinyl acetate monomer is a substance on the Domestic Substances List identified under subsection 73(1) of the Canadian Environmental Protection Act, 1999;

Whereas a summary of the final Screening Assessment Report conducted on vinyl acetate monomer pursuant to section 74 of the Act is annexed hereby; and

Whereas vinyl acetate monomer does not meet any of the criteria set out in section 64 of the Act,

Notice therefore is hereby given that the Ministers of the Environment and of Health propose to take no further action on vinyl acetate monomer at this time under section 77 of the Act.

JIM PRENTICE
Minister of the Environment

LEONA AGLUKKAQ
Minister of Health

ANNEX

Summary of the Screening Assessment Report of Acetic acid ethenyl ester

Pursuant to section 74 of the Canadian Environmental Protection Act, 1999 (CEPA 1999), the Ministers of the Environment and of Health have conducted a screening assessment of Acetic acid ethenyl ester, otherwise commonly referred to as vinyl acetate monomer, Chemical Abstracts Service Registry No. 108-05-4, a substance identified in the categorization of the Domestic Substances List as a high priority for action under the Ministerial Challenge. Vinyl acetate was identified as a high priority as it was considered to pose greatest potential for exposure to individuals in Canada and had been classified by other agencies on the basis of carcinogenicity. The substance did not meet the ecological categorization criteria for persistence, bioaccumulation or inherent toxicity to aquatic organisms. Therefore, the focus of this assessment of vinyl acetate relates to human health aspects.

According to the data submitted in response to section 71 of CEPA 1999, vinyl acetate is primarily imported into Canada, between 10 and 50 000 metric tons (2006 data), for use in the industrial synthesis of polyvinyl acetate (PVAc) and vinyl acetate (co)polymers, such as ethylene vinyl acetate or EVA copolymer. These polymers are subsequently applied in the manufacturing of various types of products for industrial and consumer applications. Vinyl acetate monomer itself has no direct use as an end-use product nor is it added intentionally; it is only found as a residue of manufacturing polymerization processes. As PVAc is used to manufacture polyvinyl alcohols, polyvinyl alcohols do not contain any residues of vinyl acetate monomer. Consumer products that may contain residues of vinyl acetate monomer include adhesives, joint sealants, caulks, latex paints, plasters, food packaging (including films) and cosmetics. Synthesized polymers, including emulsion dispersions, may undergo devolatilization processes to further reduce any trace residual amounts of monomer that remain. Such residual exposures constitute “direct” exposures, whereas “indirect” exposures occur from industrial releases during manufacturing, processing, storage and transport. The industrial releases occur primarily to ambient air as a result of vinyl acetate’s vapour pressure. In ambient air, the monomer may be degraded by free-radical hydroxylation or by ozonation. Vinyl acetate tends to remain in the environmental media to which it is released.

Based principally on the weight-of-evidence assessment of the International Agency for Research on Cancer and the European Union, a critical effect for characterization of risk to human health for vinyl acetate is carcinogenicity. Tumours of the nasal cavity in male and female rats were observed following inhalation exposure to vinyl acetate at the highest dose tested. More recent studies also reported squamous cell carcinomas of the upper digestive tract in both sexes of mice and rats following oral exposure to vinyl acetate. Vinyl acetate was also found to produce DNA-protein crosslinks and is genotoxic (clastogenic) in human cells in vitro and in animals in vivo, effects considered secondary to the metabolism of vinyl acetate to acetaldehyde, a known crosslinker.

The margins of exposure based on non-neoplastic effects (effects of the upper respiratory tract in animals and humans) and the upper-bounding estimates of exposure to the general population derived from environmental media and consumer products are adequate to account for uncertainties in the databases on exposure and effects.

On the basis of the consideration of the existence of a practical threshold for carcinogenicity of vinyl acetate in animal studies, considering the magnitude of the margins of exposure for effects, it is proposed that vinyl acetate be considered as a substance that is not entering the environment in a quantity or concentration or under conditions that constitute or may constitute a danger in Canada to human life or health.

This assessment acknowledges that vinyl acetate could pose a risk if exposures increase beyond those estimated in this screening assessment. Therefore, to ensure that consumer exposures do not increase, acceptable margins of exposure are maintained, research and monitoring will support, where relevant, verification of assumptions used and, where appropriate, the performance of potential measures identified during the risk management phase.

On the basis of ecological hazard and reported releases of vinyl acetate, it is proposed that this substance is not entering 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 that constitute or may constitute a danger to the environment on which life depends. Vinyl acetate does not meet the criteria for persistence and bioaccumulation potential as set out in the Persistence and Bioaccumulation Regulations.

This substance will be included in the upcoming Domestic Substances List inventory update initiative. In addition and where relevant, research and monitoring will support verification of assumptions used during the screening assessment.

Conclusion

Based on the information available, it is concluded that vinyl acetate monomer does not meet any of the criteria set out in section 64 of CEPA 1999.

The final Screening Assessment Report for this substance is available on the Government of Canada’s Chemical Substances Web site (www.chemicalsubstances.gc.ca).

Publication of final decision on the screening assessment of a substance — Benzene, 1,3-bis(1-isocyanato-1-methylethyl)- (tetramethyl-m-xylylene diisocyanate), CAS No. 2778-42-9 — specified on the Domestic Substances List [subsection 77(6) of the Canadian Environmental Protection Act, 1999]

Whereas tetramethyl-m-xylylene diisocyanate is a substance on the Domestic Substances List identified under subsection 73(1) of the Canadian Environmental Protection Act, 1999;

Whereas a summary of the final Screening Assessment Report conducted on tetramethyl-m-xylylene diisocyanate pursuant to section 74 of the Act is annexed hereby; and

Whereas tetramethyl-m-xylylene diisocyanate does not meet any of the criteria set out in section 64 of the Act,

Notice therefore is hereby given that the Ministers of the Environment and of Health intend to take no further action on tetramethyl-m-xylylene diisocyanate at this time under section 77 of the Act.

JIM PRENTICE
Minister of the Environment

LEONA AGLUKKAQ
Minister of Health

ANNEX

Summary of the Screening Assessment Report of Benzene, 1,3-bis(1-isocyanato-1-methylethyl)-

Pursuant to section 74 of the Canadian Environmental Protection Act, 1999 (CEPA 1999), the Ministers of the Environment and of Health have conducted a screening assessment on Benzene, 1,3-bis(1-isocyanato-1-methylethyl)- (tetramethyl-m-xylylene diisocyanate), Chemical Abstracts Service Registry No. 2778-42-9. This substance was identified as a high priority for screening assessment and included in the Ministerial Challenge because it was found to meet the ecological categorization criteria for persistence, bioaccumulation potential and inherent toxicity to non-human organisms and is believed to be in commerce in Canada.

The substance tetramethyl-m-xylylene diisocyanate was not considered to be a high priority for assessment of potential risks to human health, based upon application of the simple exposure and hazard tools developed by Health Canada for categorization of substances on the Domestic Substances List. Therefore, this assessment focuses on information relevant to the evaluation of ecological risks.

The substance tetramethyl-m-xylylene diisocyanate is an organic substance that is used as an industrial intermediate which is incorporated into various polymers. The substance is not naturally produced in the environment. No reports of manufacture in or import into Canada of this substance at or above the reporting threshold of 100 kg in the 2005 or 2006 calendar year were received in response to notices published under section 71 of CEPA 1999. However, six Canadian and two foreign companies voluntarily reported having a stakeholder interest in this substance in 2005 and 2006. Further information was not provided.

Since there were no reports of import or manufacture at or above the reporting threshold of 100 kg in 2005 or 2006, releases of this substance into the Canadian environment are presumed to be very low. Tetramethyl-m-xylylene diisocyanate reacts with water and is expected to hydrolyze rapidly in the presence of water or moisture. It is semi-volatile and may have a tendency towards sizable losses via advection when released into the air.

Based on its reactivity in the presence of moisture, tetramethyl-m-xylylene diisocyanate is not expected to be persistent in the environment. Additional consideration of the hydrolysis data for this compound suggests that this compound is rapidly degraded in water and moist environments, such as sediment and moist soils. Similarly, the role of hydrolysis and the potential metabolism/ degradation of tetramethyl-m-xylylene diisocyanate in the gut have been considered further. The substance is thus no longer expected to meet the persistence or bioaccumulation criteria as set out in the Persistence and Bioaccumulation Regulations.

For this screening assessment, a conservative exposure scenario was selected in which an industrial operation discharges into the aquatic environment. The predicted environmental concentration in water was many orders of magnitude below predicted no-effect concentrations calculated for fish.

This substance will be included in the upcoming Domestic Substances List inventory update initiative. In addition and where relevant, research and monitoring will support verification of assumptions used during the screening assessment.

Conclusion

Based on the information available, it is concluded that tetramethyl-m-xylylene diisocyanate does not meet any of the criteria set out in section 64 of CEPA 1999.

The final Screening Assessment Report for this substance is available on the Government of Canada’s Chemical Substances Web site (www.chemicalsubstances.gc.ca).

Publication of final decision on the screening assessment of a substance — Benzenesulfonic acid, 3,3 ′ -[(9,10-dihydro-9,10-dioxo-1,4-anthracenediyl)diimino]bis[2,4,6-trimethyl-, disodium salt (Acid Blue 80), CAS No. 4474-24-2 — specified on the Domestic Substances List [subsection 77(6) of the Canadian Environmental Protection Act, 1999]

Whereas Acid Blue 80 is a substance on the Domestic Substances List identified under subsection 73(1) of the Canadian Environmental Protection Act, 1999;

Whereas a summary of the final Screening Assessment Report conducted on Acid Blue 80 pursuant to section 74 of the Act is annexed hereby; and

Whereas Acid Blue 80 does not meet any of the criteria set out in section 64 of the Act,

Notice therefore is hereby given that the Ministers of the Environment and of Health intend to take no further action on Acid Blue 80 at this time under section 77 of the Act.

JIM PRENTICE
Minister of the Environment

LEONA AGLUKKAQ
Minister of Health

ANNEX

Summary of the Screening Assessment Report of Benzenesulfonic acid, 3,3′-[(9,10-dihydro-9,10-dioxo-1,4-anthracenediyl)diimino]bis[2,4,6-trimethyl-, disodium salt

Pursuant to section 74 of the Canadian Environmental Protection Act, 1999 (CEPA 1999), the Ministers of the Environment and of Health have conducted a screening assessment on Benzenesulfonic acid, 3,3′-[(9,10-dihydro-9,10-dioxo-1,4-anthracenediyl)diimino]bis[2,4,6-trimethyl-, disodium salt (Acid Blue 80), Chemical Abstracts Service Registry No. 4474-24-2. This substance was identified as a high priority for screening assessment and included in the Ministerial Challenge because it was found to meet the ecological categorization criteria for persistence, bioaccumulation potential and inherent toxicity to non-human organisms and is believed to be in commerce in Canada.

The substance Acid Blue 80 was not considered to be a high priority for assessment of potential risks to human health, based upon application of the simple exposure and hazard tools developed by Health Canada for categorization of substances on the Domestic Substances List. Therefore, this assessment focuses on information relevant to the evaluation of ecological risks.

Acid Blue 80 is a discrete organic substance that is used in Canada and elsewhere as a dark-blue colourant dye in cleaning products, in consumer products and in several industrial and commercial sectors. In addition, Acid Blue 80 is used in Canada as a dye in one disinfectant registered under the Pest Control Products Act and at low concentrations in cleaners and laundry detergents used in food plants. The substance is not naturally produced in the environment. Between 10 001 and 100 000 kg of Acid Blue 80, contained mainly in cleaning products, were imported into Canada in 2006. Such reported quantity and uses indicate that Acid Blue 80 could be released into the Canadian environment.

Based on certain assumptions and reported use patterns, most of the substance is expected to end up in surface water, with a relatively small fraction being transferred to waste disposal sites. It is not expected to be present in significant quantities in other media.

Based on its physical and chemical properties, Acid Blue 80 does not have the potential to accumulate in aquatic organisms and it does not degrade quickly in the environment. Acid Blue 80 is expected to be persistent in water, soil and sediments based on criteria defined in the Persistence and Bioaccumulation Regulations. Empirical acute aquatic toxicity values for Acid Blue 80 and an analogue suggest that the substance is not highly hazardous to aquatic organisms.

For this screening assessment, risk quotients were calculated based on two conservative exposure scenarios: one for industrial release, and one for consumer releases, both to the aquatic environment. The resulting predicted environmental concentration were all below the predicted no-effect concentrations calculated for aquatic organisms, indicating that these releases are unlikely to cause ecological harm.

This substance will be included in the upcoming Domestic Substances List inventory update initiative. In addition and where relevant, research and monitoring will support verification of assumptions used during the screening assessment.

Conclusion

Based on the information available, it is concluded that Acid Blue 80 does not meet any of the criteria set out in section 64 of CEPA 1999.

The final Screening Assessment Report for this substance is available on the Government of Canada’s Chemical Substances Web site (www.chemicalsubstances.gc.ca).

Publication of final decision on the screening assessment of a substance — Spiro[isobenzofuran-1(3H),9′-[9H]xanthen]-3-one, 2′,4′,5′,7′-tetrabromo-3′,6′-dihydroxy- (D&C Red No. 21) CAS No. 15086-94-9 — specified on the Domestic Substances List [subsection 77(6) of the Canadian Environmental Protection Act, 1999]

Whereas D&C Red No. 21 is a substance on the Domestic Substances List identified under subsection 73(1) of the Canadian Environmental Protection Act, 1999;

Whereas a summary of a final Screening Assessment Report conducted on D&C Red No. 21 pursuant to section 74 of the Act, is annexed hereby; and

Whereas D&C Red No. 21 does not meet any of the criteria set out in section 64 of the Act,

Notice therefore is hereby given that the Ministers of the Environment and of Health propose to take no further action on D&C Red No. 21 at this time under section 77 of the Act.

JIM PRENTICE
Minister of the Environment

LEONA AGLUKKAQ
Minister of Health

ANNEX

Summary of the Screening Assessment Report of Spiro[isobenzofuran-1(3H),9′-[9H]xanthen]-3-one, 2′,4′,5′,7′-tetrabromo-3′,6′-dihydroxy-

Pursuant to section 74 of the Canadian Environmental Protection Act, 1999 (CEPA 1999), the Ministers of the Environment and of Health have conducted a screening assessment on Spiro[isobenzofuran-1(3H),9′-[9H]xanthen]-3-one, 2′,4′,5′,7′-tetrabromo-3′,6′-dihydroxy- (D&C Red No. 21), Chemical Abstracts Service Registry No. 15086-94-9. This substance was identified as a high priority for screening assessment and included in the Ministerial Challenge because it was found to meet the ecological categorization criteria for persistence, bioaccumulation potential and inherent toxicity to non-human organisms and is believed to be in commerce in Canada.

The substance D&C Red No. 21 was not considered to be a high priority for assessment of potential risks to human health, based upon application of the simple exposure and hazard tools developed by Health Canada for categorization of substances on the Domestic Substances List. Therefore, this assessment focuses on information relevant to the evaluation of ecological risks.

The organic substance D&C Red No. 21 is used in Canada primarily as a dye in cosmetics. The substance is not naturally produced in the environment. Data collected pursuant to a notice published under section 71 of CEPA 1999 for the 2000 calendar year indicated that for D&C Red No. 21, one company reported potential import of the substance; however, the quantities were unknown. In response to the voluntary call for new information under the Challenge, the company that reported potential import in 2000 confirmed that their importing activity was below the 100 kg threshold in 2006. In total, less than 100 kg of D&C Red No. 21 were voluntarily reported to be imported in 2006, with a few companies reporting low quantities.

Since there were no reports of import or manufacture at or above the reporting threshold of 100 kg in 2000 or 2006, releases of this substance into the canadian environment are presumed to be very low. The substance D&C Red No. 21 will be ionized at neutral pH, and has a high solubility in water and low Log Kow. It is not volatile, and would have a tendency to remain in water when released to surface water.

Based on its predicted resistance to biodegradation, D&C Red No. 21 is expected to be persistent in the environment; however, it is subject to relatively rapid primary degradation by photolysis. New experimental data relating to its partitioning between octanol and water suggest that this dye has a low potential to accumulate in the lipid tissues of organisms. The substance is thus no longer expected to meet the persistence or bioaccumulation criterion as set out in the Persistence and Bioaccumulation Regulations. In addition, new experimental toxicity data for the dye and its chemical analogues suggest that the substance has a low acute toxicity to aquatic organisms.

For this screening assessment, a generic conservative exposure scenario was developed to estimate releases into the aquatic environment from industrial operations and resulting aquatic concentration. No adverse effects were anticipated, as the predicted environmental concentration in water was below predicted no-effect concentration.

This substance will be included in the upcoming Domestic Substances List inventory update initiative. In addition and where relevant, research and monitoring will support verification of assumptions used during the screening assessment.

Conclusion

Based on the information available, it is concluded that D&C Red No. 21 does not meet any of the criteria set out in section 64 of CEPA 1999.

The final Screening Assessment Report for this substance is available on the Government of Canada’s Chemical Substances Web site (www.chemicalsubstances.gc.ca).

Publication of final decision on the screening assessment of a substance — 9,10-Anthracenedione, 1,4-bis[(4-methylphenyl)amino]-, sulfonated, potassium salts (AMS) CAS No. 125351-99-7 — specified on the Domestic Substances List [subsection 77(6) of the Canadian Environmental Protection Act, 1999]

Whereas AMS is a substance on the Domestic Substances List identified under subsection 73(1) of the Canadian Environmental Protection Act, 1999;

Whereas a summary of a final Screening Assessment Report conducted on AMS pursuant to section 74 of the Act is annexed hereby; and

Whereas AMS does not meet any of the criteria set out in section 64 of the Act,

Notice therefore is hereby given that the Ministers of the Environment and of Health intend to take no further action on AMS at this time under section 77 of the Act.

JIM PRENTICE
Minister of the Environment

LEONA AGLUKKAQ
Minister of Health

ANNEX

Summary of the Screening Assessment Report of 9,10-Anthracenedione, 1,4-bis[(4-methylphenyl)amino]-, sulfonated, potassium salts

Pursuant to section 74 of the Canadian Environmental Protection Act, 1999 (CEPA 1999), the Ministers of the Environment and of Health have conducted a screening assessment on 9,10-Anthracenedione, 1,4-bis[(4-methylphenyl)amino]-, sulfonated, potassium salts (AMS), Chemical Abstracts Service Registry No. 125351-99-7. This substance was identified as a high priority for screening assessment and included in the Ministerial Challenge because it was originally found to meet the ecological categorization criteria for persistence, bioaccumulation potential and inherent toxicity to non-human organisms and is believed to be in commerce in Canada.

The substance AMS was not considered to be a high priority for assessment of potential risks to human health, based upon application of the simple exposure and hazard tools developed by Health Canada for categorization of substances on the Domestic Substances List. Therefore, this assessment focuses on information relevant to the evaluation of ecological risks.

AMS is an organic “unknown or variable composition, complex reaction products, and biologicals” substance that may be used in Canada and elsewhere as a blue colorant dye in textiles, printing inks, rubber, plastic products, paints, lacquers and varnishes. The substance is not naturally produced in the environment. Between 100 and 1 000 kg/year of AMS were imported into Canada in 2005 and 2006, for use mainly in the colorants and plastics industry. The quantity of AMS imported into Canada, along with the uses reported for this substance, indicate that it could potentially be released into the Canadian environment.

Based on certain assumptions and reported use patterns, most of the substance is expected to end up in waste disposal sites, but a relatively large fraction may also be released to water. It is not expected to be significantly present in other media.

Based on its physical and chemical properties, AMS does not have the potential to accumulate in aquatic organisms, and an empirical acute aquatic toxicity value suggests that the substance is not hazardous to aquatic organisms. When considered together with the low volume of AMS imported into Canada, as well as information on its uses, it is unlikely that AMS is causing ecological harm in Canada. However, AMS does not degrade quickly in the environment. It is expected to be persistent in water, soil and sediments. Therefore, the substance has been determined to meet the persistence criteria as set out in the Persistence and Bioaccumulation Regulations.

This substance will be included in the upcoming Domestic Substances List inventory update initiative. In addition and where relevant, research and monitoring will support verification of assumptions used during the screening assessment.

Conclusion

Based on the information available, it is concluded that AMS does not meet any of the criteria set out in section 64 of CEPA 1999.

The final Screening Assessment Report for this substance is available on the Government of Canada’s Chemical Substances Web site (www.chemicalsubstances.gc.ca).

Publication of final decision on the screening assessment of two substances — Benzenesulfonic acid, [(9,10-dihydro-9,10-dioxo-1,4-anthracenediyl)bis(imino-4,1-phenyleneoxy)]bis-, disodium salt (Acid Green 40:1), CAS No. 70161-19-2 and Benzenesulfonic acid, 2,2 -[(9,10-dihydro-5,8-dihydroxy-9,10-dioxo-1,4-anthracenediyl)diimino]bis[5-(1,1-dimethylethyl)-, disodium salt (ADIBSS), CAS No. 83006-67-1 — specified on the Domestic Substances List [subsection 77(6) of the Canadian Environmental Protection Act, 1999]

Whereas Acid Green 40:1 and ADIBSS are substances on the Domestic Substances List identified under subsection 73(1) of the Canadian Environmental Protection Act, 1999;

Whereas a summary of a final Screening Assessment Report conducted on Acid Green 40:1 and ADIBSS pursuant to section 74 of the Act is annexed hereby;

Whereas the Ministers of the Environment and of Health have identified no manufacture or importation activity for Acid Green 40:1 and ADIBSS above 100 kg per calendar year;

Whereas Acid Green 40:1 and ADIBSS do not meet any of the criteria set out in section 64 of the Act; and

Whereas the Minister of the Environment intends to amend the Domestic Substances List, under subsection 87(3) of the Act, to indicate that subsection 81(3) thereof applies with respect to the above substances,

Notice therefore is hereby given that the Ministers of the Environment and of Health propose to take no further action on Acid Green 40:1 and ADIBSS at this time under section 77 of the Act.

JIM PRENTICE
Minister of the Environment

LEONA AGLUKKAQ
Minister of Health

ANNEX

Summary of the Screening Assessment Report of Benzenesulfonic acid, [(9,10-dihydro-9,10-dioxo-1,4-anthracenediyl)bis(imino-4,1-phenyleneoxy)]bis-, disodium salt (Acid Green 40:1) and Benzenesulfonic acid, 2,2 -[(9,10-dihydro-5,8-dihydroxy-9,10-dioxo-1,4-anthracenediyl)diimino]bis[5-(1,1-dimethylethyl)-, disodium salt (ADIBSS)

CAS RN*

Name on the Domestic Substance List

70161-19-2

Benzenesulfonic acid, [(9,10-dihydro-9,10-dioxo-1,4-anthracenediyl)bis(imino-4,1-phenyleneoxy)]bis-, disodium salt

83006-67-1

Benzenesulfonic acid, 2,2 -[(9,10-dihydro-5,8-dihydroxy-9,10-dioxo-1,4-anthracenediyl)diimino]bis[5-(1,1-dimethylethyl)-, disodium salt

*CAS RN = Chemical Abstracts Service Registry Number

The above two substances on the Domestic Substances List were identified as high priorities for screening assessment, to be part of the Ministerial Challenge, because they met the ecological categorization criteria for persistence (P) and bioaccumulation (B) and inherent toxicity to non-human organisms (iT), under paragraph 73(1)(b) of the Canadian Environmental Protection Act, 1999 (CEPA 1999), and were believed to be in commerce in Canada. The substances were not considered to be a high priority for assessment of potential risks to human health.

Pursuant to paragraph 74(a) of CEPA 1999, the Ministers of the Environment and of Health have conducted a screening assessment on the two substances, which have persistence, bioaccumulation and inherent toxicity properties to non-human organisms.

Results from notices issued under paragraph 71(1)(b) of CEPA 1999 in March 2006 and May 2007 revealed no reports of industrial activity (import or manufacture) with respect to these substances in Canada, above the reporting threshold of 100 kg, for the specified reporting years of 2005 and 2006. These results suggest that these substances are currently not in use above the specified reporting threshold, and therefore the likelihood of exposure to these substances in Canada resulting from commercial activity is low.

Results from the above notices issued under paragraph 71(1)(b) of CEPA 1999 and the accompanying questionnaire of May 2007 also revealed no new information relevant to the PBiT properties of these two substances. Given the lack of any significant commercial activity for these substances, no additional efforts have been made to collect or analyze information relevant to the persistence, bioaccumulation and ecological effects of these two substances beyond what was done for categorization. Therefore, the decisions on PBiT properties made during categorization remain unchanged. The substances are considered to be inherently toxic to non-human organisms. They also meet the criteria for both persistence and bioaccumulation as set out in the Persistence and Bioaccumulation Regulations.

Conclusion

Based on available information, and until new information is received indicating that either of the substances is entering, or may enter the environment, it is proposed that Acid Green 40:1 and ADIBSS are currently not entering, nor are they likely to enter, the environment as a result of commercial activity in Canada. Therefore, Acid Green 40:1 and ADIBSS do not meet the criteria set out in section 64 of CEPA 1999.

As substances listed on the Domestic Substances List, import and manufacture of these two substances in Canada are not subject to notification under subsection 81(1). Given their hazardous PBiT properties, there is concern that new activities for the above two substances which have not been identified or assessed under CEPA 1999 could lead to the substances meeting the criteria set out in section 64 of the Act. Therefore it is recommended that the above two substances be subject to the Significant New Activity provisions specified under subsection 81(3) of the Act, to ensure that any new manufacture, import or use of these substances in quantities greater than 100 kg/year is notified and will undergo ecological and human health risk assessments as specified in section 83 of the Act, prior to the substance being introduced into Canada.

Publication of final decision on the screening assessment of a substance — Octamethylcyclotetrasiloxane (D4), CAS No. 556-67-2 — specified on the Domestic Substances List [subsection 77(6) of the Canadian Environmental Protection Act, 1999]

Whereas D4 is a substance on the Domestic Substances List identified under subsection 73(1) of the Canadian Environmental Protection Act, 1999;

Whereas a summary of the final Screening Assessment Report conducted on D4 pursuant to section 74 of the Act is annexed hereby; and

Whereas D4 meets one or more of the criteria set out in section 64 of the Act,

Notice therefore is hereby given that the Ministers of the Environment and of Health intend to recommend to Her Excellency the Governor in Council that D4 be added to Schedule 1 to the Act.

Notice is furthermore given that the Ministers of the Environment and of Health have released a proposed risk management approach document, for a public comment period of 60 days, to continue discussions with stakeholders regarding the risk management actions for this substance.

Public comment period on the proposed risk management approach document

Any person may, within 60 days after publication of the proposed risk management approach document, file with the Minister of the Environment written comments on the risk management approach document. More information regarding the proposed risk management approach may be obtained from the Government of Canada’s Chemical Substances Web site (www.chemicalsubstances.gc.ca). All comments must cite the Canada Gazette, Part I, and the date of publication of this notice and be sent to the Executive Director, Existing Substances Division, Gatineau, Quebec K1A 0H3, 1-800-410-4314 or 819-953-4936 (fax), or by email to Existing.Substances.Existantes@ec.gc.ca.

In accordance with section 313 of the Canadian Environmental Protection Act, 1999, any person who provides information in response to this notice may submit with the information a request that it be treated as confidential.

JIM PRENTICE
Minister of the Environment

LEONA AGLUKKAQ
Minister of Health

ANNEX

Summary of the Screening Assessment Report of Octamethylcyclotetrasiloxane

Pursuant to section 74 of the Canadian Environmental Protection Act, 1999 (CEPA 1999), the Ministers of the Environment and of Health have conducted a screening assessment on Octamethylcyclotetrasiloxane (D4), Chemical Abstracts Service Registry No. 556-67-2. During the categorization process, this substance was identified as a high priority for screening assessment and included in the Ministerial Challenge because it had been considered to pose an intermediate potential for exposure to individuals in Canada and has been classified by another agency on the basis of reproductive toxicity. Further, it had initially been found to meet the ecological categorization criteria for persistence, bioaccumulation potential and inherent toxicity to non-human organisms and it is known to be in commerce in Canada.

Octamethylcyclotetrasiloxane, or D4, is an industrial chemical which was not manufactured by any company in Canada in 2006 in a quantity above the reporting threshold of 100 kg, but which was imported into the country in 2006 at a total quantity between 1 000 000 and 10 000 000 kg as an essentially pure substance, in mixtures with other cyclic siloxanes, as a residual in silicone polymers, and in finished consumer products.

The principal sources of release of D4 to the environment are industrial processes in which it is reacted to form silicone polymers, from blending, formulation and packaging operations. It is also released from the use and disposal of personal care products. Air, wastewater and agricultural soil are the principal receiving environmental media for D4 based on its physical-chemical properties and its use patterns.

In air, D4 is persistent with calculated atmospheric half-lives of more than five days. D4 has the potential to be transported over long distances in the atmosphere. However, it has a low potential to be deposited in water or soil in remote regions. The hydrolysis half-lives for D4 under Canadian water conditions (pH 6–9, temperature 5°–25°C) are estimated to range from hours to 45 days, indicating the substance is not persistent in water. The final hydrolysis product dimethylsilanediol is expected to biodegrade quite slowly. D4 degradation in sediment appears to be much slower with half-lives of 49 to 588 days estimated under realistic Canadian sediment conditions (temperature of 5°–25°C), indicating the substance may be persistent in sediment. D4 is not considered persistent in soil, based on evidence of clay-catalyzed degradation, with dimethylsilanediol being the stable hydrolysis product. Therefore, D4 has been determined to meet the persistence criteria as set out in the Persistence and Bioaccumulation Regulations.

The empirical bioconcentration factor and modelled bioaccumulation factor are both above 5 000, indicating D4 may have a high potential to accumulate in aquatic organisms. However, data from a biomagnification study in fish and a biota-sediment accumulation study in invertebrates suggest that the bioaccumulation potential of D4 may be lower, possibly due to reduced bioavailability. Therefore, while D4 has the potential to accumulate in biota, it is not possible to conclude at this time that D4 meets the criteria for bioaccumulation as set out in the Persistence and Bioaccumulation Regulations based on consideration of the conflicting evidence from laboratory studies and predictive models.

Adverse effects from exposure to D4 in sediment-dwelling organisms were observed at concentrations above 44 mg/kg. The experimental toxicity data show that the substance can also cause long-term toxicity to sensitive pelagic aquatic organisms at relatively low concentrations (below its water solubility limit of 0.056 mg/L). Risk quotients derived from exposure scenarios involving discharges of D4 from both consumer use and industrial operations show a total of 249 sites (approximately 23.4%) evaluated across Canada have predicted environmental concentrations in water higher than predicted no-effect concentrations for aquatic organisms. Considering D4’s potential to bioaccumulate in biota and its high toxicity to sensitive aquatic organisms, long-term environmental exposure to D4 may cause adverse effects to aquatic organisms in certain Canadian environments. Based on this evidence, it is concluded that D4 has the potential to cause ecological harm.

Based principally on the weight-of-evidence-based assessments of the European Commission and the Danish Environmental Protection Agency, an important effect of D4 exposure is impaired fertility. However, the Danish Environmental Protection Agency also identified the liver as a target organ for D4 exposures. The critical effect level for repeated-dose toxicity via inhalation was based not only on increased liver weights, but also on effects observed in other organs (adrenals, thymus, lungs) in a three-month rat inhalation study. Comparison of the critical effect level for repeated-dose effects via inhalation and the conservative upper-bounding exposure estimate via inhalation for D4 results in an adequate margin of exposure. The critical effect level for repeated-dose toxicity via the oral route was based on decreased serum estradiol in seven-day mouse studies and decreased body-weights and relative liver weights in fetuses in eight-day rat studies (D4 administered to pregnant females). Comparison of the critical effect level for repeated-dose effects via the oral route and the upper-bounding estimate of daily intake of D4 by the general population in Canada results in an adequate margin of exposure.

Based on an independent review of a refined exposure assessment for personal care products, an adequate margin of exposure was derived by comparison of the critical effect level for repeateddose effects via the oral route and a conservative upper-bounding estimate of daily intake of D4 via use of personal care products.

Based on the available information on its potential to cause ecological harm, it is concluded that D4 is entering 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.

Based on the available information on its potential to cause harm to human health, it is concluded that D4 is not entering the environment in a quantity or concentration or under conditions that constitute or may constitute a danger in Canada to human life or health.

This substance will be included in the upcoming Domestic Substances List inventory update initiative. In addition and where relevant, research and monitoring will support verification of assumptions used during the screening assessment and, where appropriate, the performance of potential control measures identified during the risk management phase.

Conclusion

Based on the information available, it is concluded that D4 meets one or more of the criteria set out in section 64 of CEPA 1999.

The final Screening Assessment Report as well as the proposed risk management approach document for this substance are available on the Government of Canada’s Chemical Substances Web site (www.chemicalsubstances.gc.ca).

Publication of final decision on the screening assessment of a substance — Decamethylcyclopentasiloxane (D5) CAS No. 541-02-6 — specified on the Domestic Substances List [subsection 77(6) of the Canadian Environmental Protection Act, 1999]

Whereas D5 is a substance on the Domestic Substances List identified under subsection 73(1) of the Canadian Environmental Protection Act, 1999;

Whereas a summary of the final Screening Assessment Report conducted on D5 pursuant to section 74 of the Act is annexed hereby; and

Whereas D5 meets one or more of the criteria set out in section 64 of the Act,

Notice therefore is hereby given that the Ministers of the Environment and of Health intend to recommend to Her Excellency the Governor in Council that D5 be added to Schedule 1 to the Act.

Notice is furthermore given that the Ministers of the Environment and of Health have released a proposed risk management approach document, for a public comment period of 60 days, to continue discussions with stakeholders regarding the risk management actions for this substance.

Public comment period on the proposed risk management approach document

Any person may, within 60 days after publication of the proposed risk management approach document, file with the Minister of the Environment written comments on the risk management approach document. More information regarding the proposed risk management approach may be obtained from the Government of Canada’s Chemical Substances Web site (www.chemicalsubstances.gc.ca). All comments must cite the Canada Gazette, Part I, and the date of publication of this notice and be sent to the Executive Director, Existing Substances Division, Gatineau, Quebec K1A 0H3, 1-800-410-4314 or 819-953-4936 (fax), or by email to Existing.Substances.Existantes@ec.gc.ca.

In accordance with section 313 of the Canadian Environmental Protection Act, 1999, any person who provides information in response to this notice may submit with the information a request that it be treated as confidential.

JIM PRENTICE
Minister of the Environment

LEONA AGLUKKAQ
Minister of Health

ANNEX

Summary of the Screening Assessment Report of Decamethylcyclopentasiloxane

Pursuant to section 74 of the Canadian Environmental Protection Act, 1999 (CEPA 1999), the Ministers of the Environment and of Health have conducted a screening assessment on Decamethylcyclopentasiloxane (D5), Chemical Abstracts Service Registry No. 541-02-6. During the categorization process, this substance was identified as a high priority for screening assessment and included in the Ministerial Challenge because it had been initially found to meet the ecological categorization criteria for persistence, bioaccumulation potential and inherent toxicity to non-human organisms and it is known to be in commerce in Canada.

Although the categorization exercise did not determine D5 to be a priority for assessment of potential risks to human health, a human health assessment of D5 was also conducted due to its structure and use pattern similarity to D4, Octamethylcyclotetrasiloxane (also known as D4), a high priority for assessment for both human health and ecological risks under CEPA 1999.

D5 is an industrial chemical which was not manufactured in Canada in 2006 in a quantity above the reporting threshold of 100 kg, but which is imported into the country as an essentially pure substance, in mixtures with other cyclic siloxanes, as a residual in silicone polymers, and in finished consumer products. From responses to a notice published under section 71 of CEPA 1999, it was determined that between 1 000 000 and 10 000 000 kg of D5 were imported into Canada in 2006.

D5 may be released to the environment from industrial processes such as blending, formulation and packaging operations, and from its use as an industrial defoamer and degreaser. It is also released from the use and disposal of personal care products. Air, wastewater, and agriculture soil are the principal receiving environmental media for D5 based on its physical-chemical properties and its use patterns.

In air, D5 is persistent with calculated atmospheric half-lives of more than three days. D5 has the potential to be transported over long-distances in the atmosphere. However, it has a low potential to be deposited in water or soil in remote regions. The hydrolysis half-lives for D5 under Canadian water conditions ranged from 1 to 733 days, indicating the substance is persistent under certain Canadian water conditions, especially in cooler and neutral water (5°–10°C). D5 is also judged to be persistent in sediment, with half-lives of 49 to 588 days estimated under realistic Canadian sediment conditions (temperature of 5°–25°C) based on information to structurally similar analogue D4, indicating the substance may be persistent in sediment. D5 is not considered persistent in soil, based on evidence of clay-catalyzed degradation, with dimethylsilanediol being the stable hydrolysis product. Therefore, D5 has been determined to meet the persistence criterion as set out in the Persistence and Bioaccumulation Regulations.

The empirical bioconcentration factor and modelled bioaccumulation factor are both above 5 000, indicating D5 may have a high potential to accumulate in aquatic organisms. However, data from a biomagnification study in fish and a biota-sediment accumulation study in invertebrates suggest that the bioaccumulation potential of D5 may be lower, possibly due to reduced bioavailability. Therefore, while D5 has the potential to accumulate in biota, it is not possible to conclude at this time that D5 meets the criterion for bioaccumulation as set out in the Persistence and Bioaccumulation Regulations based on consideration of the conflicting evidence from laboratory studies and predictive models.

Adverse effects from exposure to D5 in sediment-dwelling organisms were observed at a concentration of 160 mg/kg. The experimental toxicity data showed no adverse effects to pelagic aquatic organisms at concentrations up to 0.015 mg/L, its approximate water solubility limit. However, it is possible that toxicity may manifest at the solubility limit if sufficient exposure and sensitive species were present. Risk quotients derived from exposure scenarios involving discharges of D5 from both consumer use and industrial operations show that a total of 65 sites (approximately 6.8%) evaluated across Canada have predicted environmental concentrations in water higher than the 0.015 mg/L predicted no-effect concentration, without the use of an application factor, for aquatic organisms. Considering the persistence of D5 under colder Canadian water conditions and its potential to bioaccumulate in biota, long-term environmental exposure to D5 may potentially cause adverse effects to aquatic organisms in certain Canadian environments.

Based principally on the weight-of-evidence-based assessment of the Danish EPA, a potential effect for repeated-dose toxicity is carcinogenicity, as observed in a two-year rat study. It is noted that the uterine tumours in this study were observed at higher levels than the effects identified for the lung and liver in several other toxicity studies. The lung was identified as a target organ for inhalation exposures of D5 whereas the liver was identified as a target organ for oral and inhalation exposures. The critical effect level for repeated dose toxicity via the inhalation route was based on a significant increased incidence of pulmonary vascular mineralization as observed in a rat reproduction study. Comparison of the critical effect level for repeated dose effects via inhalation and the conservative upper-bounding exposure estimate via inhalation for Decamethylcyclotetrasiloxane, results in adequate margins of exposure. The critical effect level for repeated-dose toxicity was based on increased liver weight in a 90-day rat study and using, as support, the determinations of oral critical effect levels for the similar compounds Octamethylcyclotetrasiloxane and Dodecamethylcyclohexasiloxane. Based on an independent review of a refined exposure assessment for personal care products, an adequate margin of exposure was derived by comparison of the critical effect level for repeated dose effects via the oral route and a conservative upper-bounding estimate of daily intake of D5 via use of personal care products.

Based on the available information on its potential to cause ecological harm, it is concluded that D5 is entering 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.

Based on the available information on its potential to cause harm to human health, it is concluded that D5 is not entering the environment in a quantity or concentration or under conditions that constitute or may constitute a danger in Canada to human life or health.

This substance will be included in the upcoming Domestic Substances List inventory update initiative. In addition and where relevant, research and monitoring will support verification of assumptions used during the screening assessment and, where appropriate, the performance of potential control measures identified during the risk management phase.

Conclusion

Based on the information available, it is concluded that D5 meets one or more of the criteria set out in section 64 of CEPA 1999.

The final Screening Assessment Report as well as the proposed risk management approach document for this substance are available on the Government of Canada’s Chemical Substances Web site (www.chemicalsubstances.gc.ca).

Publication of final decision on the screening assessment of a substance — Dodecamethylcyclohexasiloxane (D6), CAS No. 540-97-6 — specified on the Domestic Substances List [subsection 77(6) of the Canadian Environmental Protection Act, 1999]

Whereas D6 is a substance on the Domestic Substances List identified under subsection 73(1) of the Canadian Environmental Protection Act, 1999;

Whereas a summary of the final Screening Assessment Report conducted on D6 pursuant to section 74 of the Act is annexed hereby; and

Whereas D6 does not meet any of the criteria set out in section 64 of the Act,

Notice therefore is hereby given that the Ministers of the Environment and of Health propose to take no further action on D6 at this time under section 77 of the Act.

JIM PRENTICE
Minister of the Environment

LEONA AGLUKKAQ
Minister of Health

ANNEX

Summary of the Screening Assessment Report of Dodecamethylcyclohexasiloxane

Pursuant to section 74 of the Canadian Environmental Protection Act, 1999 (CEPA 1999), the Ministers of the Environment and of Health have conducted a screening assessment on Dodecamethylcyclohexasiloxane (D6), Chemical Abstracts Service Registry No. 540-97-6. During the categorization process, this substance was identified as a high priority for screening assessment and included in the Ministerial Challenge because it had been initially found to meet the ecological categorization criteria for persistence, bioaccumulation potential and inherent toxicity to non-human organisms and it is known to be in commerce in Canada.

Although the categorization exercise did not determine D6 to be a priority for assessment of potential risks to human health, a human health assessment of D6 was also conducted due to its structure and use pattern similarity to Octamethylcyclotetrasiloxane (also known as D4), a high priority for assessment for both human health and ecological risks under CEPA 1999.

D6 is an industrial chemical which was not manufactured in Canada in 2006 in a quantity above the reporting threshold of 100 kg, but which is imported into the country in mixtures with other cyclic siloxanes, as a residual in silicone polymers, and in finished consumer products. From responses to a notice published under section 71 of CEPA 1999, it was determined that between 100 000 and 1 000 000 kg of D6 were imported into Canada in 2006.

D6 may be released to the environment from industrial processes such as blending, formulation and packaging and from its use as an industrial defoamer and degreaser. It is also released from the use and disposal of personal care products. Air, wastewater, and agricultural soil are the principal receiving environmental media for D6 based on its physical-chemical properties and its use patterns.

In air, D6 is persistent with calculated atmospheric half-lives of more than two days. D6 has the potential to be transported over long distances in the atmosphere. However, it has a low potential to be deposited in water or soil in remote regions. The hydrolysis half-life for D6 is expected to be longer than that of its structurally similar analogues, D4 and D5. A half-life of approximately 401 days was extrapolated for D6 based on the experimental hydrolysis half-lives of D4 and D5 at neutral pH and ambient temperature. D6 is therefore considered persistent under typical Canadian water conditions. In sediment, D6 is expected to have a half-life longer than 49 to 588 days under realistic Canadian sediment conditions (temperature of 5°–25°C), indicating that D6 may be persistent in sediment. D6 is not considered persistent in soil, based on evidence of clay-catalyzed degradation, with dimethylsilanediol being the stable hydrolysis product. It is therefore concluded that D6 meets the persistence criteria as set out in the Persistence and Bioaccumulation Regulations.

The empirical bioconcentration factor is less than 2 000, consistent with decreased bioavailability of the substance due to its high log Kow value. The read-across laboratory biomagnification factor values from D4 and D5 indicate that D6 does not biomagnify in the test fish from dietary uptake. Although a modelled bioaccumulation factor over 5 000 suggested that the bioaccumulation potential of D6 is high, the predicted bioaccumulation factor alone is not considered to provide sufficient weight to conclude that D6 has a high bioaccumulation potential due to a high degree of uncertainty in this prediction. Thus, while D6 may have some bioaccumulation potential in biota, it is concluded, based on empirical bioconcentration factor data and read-across evidence, that D6 does not meet the bioaccumulation criteria as set out in the Persistence and Bioaccumulation Regulations.

Information on the toxicity of D6 to sediment-dwelling organisms is not available; a conservative read-across from D5 was applied and it is concluded that the no-effect concentration for D6 to the benthic community is above 69 mg/kg. The experimental toxicity data showed no adverse effects to pelagic aquatic organisms at concentrations up to 0.0046 mg/L, its approximate water solubility limit. However, reduced bioavailability compared to its close analogues, D4 and D5, suggests that no toxic threshold for adverse effect is expected for D6 at its water solubility limit. Given the low bioavailability and low potential for effects, it is concluded that D6 has low potential to cause ecological harm.

With respect to human health, the liver was identified as a target organ for oral exposures and potentially inhalation exposures of D6. The critical effect level for repeated-dose toxicity was based on increased liver weight, periportal lipidosis and thyroid follicular cell hypertrophy in a four-week rat study. Comparison of the critical effect level for repeated-dose effects via the oral route and the upper-bounding estimates of daily intake of D6 by the general population in Canada results in an adequate margin of exposure. Based on an independent review of a refined exposure assessment for personal care products, an adequate margin of exposure was derived by comparison of the critical effect level for repeated-dose effects via the oral route and the conservative upper-bounding estimate of daily intake of D6 via personal care products.

Based on the available information on its potential to cause ecological harm, it is concluded that D6 is not entering 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 that constitute or may constitute a danger to the environment on which life depends.

Based on the available information on its potential to cause harm to human health, it is concluded that D6 is not entering the environment in a quantity or concentration or under conditions that constitute or may constitute a danger in Canada to human life or health.

This substance will be included in the upcoming Domestic Substances List inventory update initiative. In addition and where relevant, research and monitoring will support verification of assumptions used during the screening assessment and, where appropriate, the performance of potential control measures identified during the risk management phase.

Conclusion

Based on the information available, it is concluded that D6 does not meet any of the criteria set out in section 64 of CEPA 1999.

The final Screening Assessment Report for this substance is available on the Government of Canada’s Chemical Substances Web site (www.chemicalsubstances.gc.ca).