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Vol. 144, No. 10 — March 6, 2010

DEPARTMENT OF THE ENVIRONMENT

DEPARTMENT OF HEALTH

CANADIAN ENVIRONMENTAL PROTECTION ACT, 1999

Publication of Final Decision after Screening Assessment of Substances — Batch 7

CAS No. 96-29-7
CAS No. 90-94-8
CAS No. 6407-74-5
CAS No. 6407-78-9
CAS No. 1325-86-6
CAS No. 6786-83-0
CAS No. 29398-96-7
CAS No. 78-59-1
CAS No. 123-91-1
CAS No. 72968-82-2
CAS No. 106276-78-2
CAS No. 16586-42-8
CAS No. 25176-89-0

Publication of Results of Investigations and Recommendations for a Substance

CAS No. 2426-08-6

Publication of results of investigations and recommendations for a substance Oxirane, (butoxymethyl)- (n-butyl glycidyl ether), CAS No. 2426-08-6 — specified on the Domestic Substances List (paragraphs 68(b) and (c) of the Canadian Environmental Protection Act, 1999)

Whereas Oxirane, (butoxymethyl)- hereafter referred to as n-butyl glycidyl ether is a substance identified as a high priority for action under the Challenge, published in the Canada Gazette, Part I, on December 9, 2006;

Whereas the summary of the final Screening Assessment conducted on n-butyl glycidyl ether under paragraph 68(b) of the Canadian Environmental Protection Act, 1999 is annexed hereby; and

Whereas n-butyl glycidyl ether 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 propose to recommend to Her Excellency the Governor in Council that n-butyl glycidyl ether be added to Schedule 1 to the Act.

Notice is furthermore given that the Ministers of the Environment and of Health are releasing a proposed risk management approach document for this substance on the Government of Canada’s Chemical Substances Web site (www.chemicalsubstances.gc.ca) to continue discussions with stakeholders on the manner in which the Ministers intend to develop a proposed regulation or instrument respecting preventive or control actions in relation to the 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 proposed 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, Program Development and Engagement Division, Gatineau, Quebec K1A 0H3, 819-953-7155 (fax), Existing.Substances.Existantes@ec.gc.ca (email).

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 of Oxirane, (butoxymethyl)- (n-butyl glycidyl ether)

The Ministers of the Environment and of Health have conducted a screening assessment of Oxirane, (butoxymethyl)-, also known as n-butyl glycidyl ether, Chemical Abstracts Service Registry No. 2426-08-6. This substance was identified in the categorization of the Domestic Substances List as a high priority for action under the Challenge. n-Butyl glycidyl ether was identified as a substance presenting an intermediate potential for exposure of individuals in Canada and had been classified by other agencies on the basis of carcinogenicity and genotoxicity. As n-butyl glycidyl ether did not meet the criteria for persistence, bioaccumulation or inherent toxicity to aquatic organisms, the focus of this assessment relates primarily to human health aspects.

According to data submitted in response to section 71 of the Canadian Environmental Protection Act, 1999 (CEPA 1999), no companies in Canada reported manufacturing n-butyl glycidyl ether in a quantity greater than or equal to the threshold of 100 kg for the 2006 calendar year. However, it was reported that 10 000–100 000 kg were imported into Canada in 2006. n-Butyl glycidyl ether is used as a reactive diluent for epoxy resins serving as a viscosity reducer, as a chemical intermediate and as an acid acceptor for stabilizing chlorinated solvents. In Canada, n-butyl glycidyl ether is used mainly in epoxy resin formulations, which have applications as coatings, adhesives, binders, sealants, fillers and resins.

Emissions of n-butyl glycidyl ether into the ambient environment would likely come from anthropogenic sources, specifically commercial production and use of epoxy resins. Based on reported releases, uses and physicochemical properties, the principal route of exposure for the general population will likely be inhalation of contaminated air; exposure by other routes and from other media is likely to be negligible.

Based on its physical and chemical properties, n-butyl glycidyl ether is not expected to be persistent or to bioaccumulate in the environment. The substance does not meet the persistence criteria or the bioaccumulation criteria as set out in the Persistence and Bioaccumulation Regulations. In addition, empirical acute aquatic toxicity data suggest that the substance poses a low to moderate hazard to aquatic organisms. Based on a comparison of predicted no toxic effect concentrations and conservatively estimated environmental exposure concentrations, it is concluded that n-butyl glycidyl ether 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 no long-term carcinogenicity assays have been conducted with n-butyl glycidyl ether, the substance was genotoxic in several in vivo and in vitro assays. In addition, substances that are structural analogues of n-butyl glycidyl ether have been demonstrated to be carcinogenic in experimental animals and genotoxic in a range of in vivo and in vitro assays. On the basis of the positive genotoxicity results for n-butyl glycidyl ether and the genotoxicity and carcinogenicity of substances analogous to n-butyl glycidyl ether, it is concluded that n-butyl glycidyl ether is a substance for which there may be a probability of harm at any level of exposure. Therefore, it is concluded that n-butyl glycidyl ether 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.

Where relevant, research and monitoring will support verification of assumptions used during the screening assessment.

Conclusion

Based on the information available, n-butyl glycidyl ether meets one or more criteria set out in section 64 of CEPA 1999.

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

Publication of final decision after screening assessment of a substance2-Butanone, oxime (butanone oxime), CAS No.96-29-7 — specified on the Domestic Substances List (subsection 77(6) of the Canadian Environmental Protection Act, 1999)

Whereas 2-Butanone, oxime (butanone oxime) 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 conducted on butanone oxime pursuant to section 74 of the Act is annexed hereby; and

Whereas butanone oxime 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 propose to recommend to Her Excellency the Governor in Council that butanone oxime be added to Schedule 1 to the Act.

Notice is furthermore given that the Ministers of the Environment and of Health are releasing a proposed risk management approach document for this substance on the Government of Canada’s Chemical Substances Web site (www.chemicalsubstances.gc.ca) to continue discussions with stakeholders on the manner in which the Ministers intend to develop a proposed regulation or instrument respecting preventive or control actions in relation to the 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 proposed 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, Program Development and Engagement Division, Gatineau, Quebec K1A 0H3, 819-953-7155 (fax), Existing.Substances.Existantes@ec.gc.ca (email).

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 of 2-Butanone, oxime (butanone oxime)

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 2-Butanone, oxime (butanone oxime), Chemical Abstracts Service Registry No. 96-29-7. This substance was identified in the categorization of the Domestic Substances List as a high priority for action under the Ministerial Challenge. Butanone oxime was identified as a high priority as it was considered to pose greatest potential for exposure of individuals in Canada and had been classified by the European Commission on the basis of carcinogenicity. Although butanone oxime met the ecological categorization criteria for persistence, it did not meet the criteria for bioaccumulation potential or inherent toxicity to aquatic organisms. Therefore, the focus of this assessment of 2-Butanone, oxime relates primarily to human health risks.

Butanone oxime is widely used as an anti-skinning agent in the formulation of alkyd paints, varnishes, stains and coatings for both industrial and consumer use. In Canada, the substance has also been reported in a number of pesticide products, wood preservatives and antifouling marine paints, as well as in some adhesives, silicone sealants and printing inks. Furthermore, butanone oxime is used as a corrosion inhibitor in industrial boilers and water treatment systems and serves as a blocking agent in the manufacturing process of urethane polymers.

According to the information submitted under section 71 of CEPA 1999, butanone oxime was not manufactured by any company in Canada in the 2006 calendar year. However, approximately 500 000 kg of the substance was imported in 2006, and nearly 120 000 kg was used in the same reporting year. There are little data on the release and fate of butanone oxime in environmental media in Canada or elsewhere. Butanone oxime is not a naturally occurring substance; thus, releases of the substance to the environment are expected to result directly from anthropogenic activities. Considering the quantity of butanone oxime in commerce in Canada and its use in a variety of consumer products, exposure of the general population to the substance is expected to be moderate.

As butanone oxime was classified on the basis of carcinogenicity by the European Commission, carcinogenicity was a key focus for this screening assessment. Increased incidences of liver tumours were observed in rat and mouse lifetime studies, and there was also an increased incidence of mammary gland tumours in female rats; however, this was seen only at moderate and/or high concentrations of butanone oxime. Consideration of the available information regarding genotoxicity indicates that butanone oxime is not likely to be genotoxic. Accordingly, although the mode of induction of tumours is not fully elucidated, the tumours observed are not considered to have resulted from direct interaction with genetic material. Therefore, a threshold approach is used to assess risk to human health.

Non-neoplastic effects were observed in the nasal cavity of rats and/or mice in inhalation studies of short-term through to chronic exposure duration. Also, repeated-dose studies based on oral exposure showed effects in the spleen, liver and kidney of rats as well as hematological effects in both rats and rabbits. Based on comparison of estimated exposures to butanone oxime in Canada with the critical effect levels, and taking into account the uncertainties in the databases on exposure and effects, it is considered that the resulting margins of exposure, particularly for consumer exposure from products containing the substance, may not be adequately protective of human health for non-cancer effects.

On the basis of the potential inadequacy of the margins between estimated exposures to butanone oxime and critical effect levels, it is concluded that butanone oxime 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 estimated releases of butanone oxime, it is concluded that the 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. Butanone oxime does meet the criteria for persistence but does not meet the criteria for bioaccumulation potential as set out in the Persistence and Bioaccumulation Regulations.

This substance will be considered for inclusion in the 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, butanone oxime meets one or more criteria set out in section 64 of CEPA 1999.

The final Screening Assessment 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 after screening assessment of a substanceMethanone, bis[4-(dimethylamino)phenyl]- (Michler’s ketone), CAS No. 90-94-8 — specified on the Domestic Substances List (subsection 77(6) of the Canadian Environmental Protection Act, 1999)

Whereas Methanone, bis[4-(dimethylamino)phenyl]- (Michler’s ketone) 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 conducted on Michler’s ketone pursuant to section 74 of the Act is annexed hereby; and

Whereas Michler’s ketone 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 propose to recommend to Her Excellency the Governor in Council that Michler’s ketone be added to Schedule 1 to the Act.

Notice is furthermore given that the Ministers of the Environment and of Health are releasing a proposed risk management approach document for this substance on the Government of Canada’s Chemical Substances Web site (www.chemicalsubstances.gc.ca) to continue discussions with stakeholders on the manner in which the Ministers intend to develop a proposed regulation or instrument respecting preventive or control actions in relation to the 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 proposed 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, Program Development and Engagement Division, Gatineau, Quebec K1A 0H3, 819-953-7155 (fax), Existing.Substances.Existantes@ec.gc.ca (email).

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 of Methanone, bis[4-(dimethylamino)phenyl]- (Michler’s ketone)

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 Methanone, bis[4-(dimethylamino)phenyl]- (Michler’s ketone), Chemical Abstracts Service Registry No. 90-94-8. The substance Michler’s ketone was identified in the categorization of the Domestic SubstancesList as a high priority for action under the Challenge. Michler’s ketone was identified as a high priority as it was considered to pose intermediate potential for exposure of individuals in Canada and is classified by the European Commission and the United States National Toxicology Program on the basis of carcinogenicity. The substance met the ecological categorization criteria for persistence, but did not meet the ecological criteria for bioaccumulation potential or inherent toxicity to aquatic organisms. Therefore, the focus of this assessment of Michler’s ketone relates primarily to human health risks.

Michler’s ketone is an organic substance that is found in Canada and elsewhere primarily as a residual in colourants resulting from an intermediary reaction during manufacturing and in final consumer products. Approximately 800 kg of Michler’s ketone were imported into Canada in 2006, whereas no manufacturing was reported in Canada for that year. Between 1 000 and 10 000 kg of Michler’s ketone were used in Canada in 2006. In Canada, most Michler’s ketone is used in paper products; minor uses include its industrial use in dry films and in electronics manufacturing.

The quantities and types of uses of Michler’s ketone imported into and used in Canada suggest that it could be released into the Canadian environment. Exposures of the general population to Michler’s ketone through environmental media are estimated to be negligible. Based on the information obtained on current uses of Michler’s ketone in Canada, exposure of the general population is expected to be very low and limited to the use of paper products containing the chemical as a manufacturing residual in paper colourants. The general population is unlikely to be exposed to Michler’s ketone from other consumer products.

Based principally on the weight-of-evidence-based assessments of international or other national agencies, a critical effect for the characterization of risk to human health for Michler’s ketone is carcinogenicity. In standard two-year carcinogenicity studies with rats and mice exposed orally to Michler’s ketone in the diet, increased incidences of hepatocellular carcinomas were observed in male and female rats and female mice, and increased incidences of hemangiosarcomas were observed in male mice. Michler’s ketone was genotoxic in a range of in vivo and in vitro assays. In addition, Michler’s ketone bound to liver deoxyribonucleic acid (DNA) and caused liver DNA damage in experimental animals. Although the modes of induction of tumours by Michler’s ketone have not been developed and elucidated, the tumours observed in the experimental animals are considered to have resulted from direct interaction with genetic material.

The non-cancer critical effect for characterization of risk to human health for Michler’s ketone is reduced body weight gain. However, tumours were observed at the lowest-observed-adverse-effect level (LOAEL) identified for the non-cancer endpoint. Thus, margins of exposure are not derived for this substance.

On the basis of the carcinogenic potential of Michler’s ketone, for which there may be a probability of harm at any exposure level, and the evidence that tumours are observed at the lowest doses tested, it is concluded that Michler’s ketone 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.

Based on its physical and chemical properties, Michler’s ketone is expected to be persistent in water, soil and sediment but is not expected to be persistent in air and is not expected to bioaccumulate in the environment. The substance therefore meets the persistence criteria but does not meet the bioaccumulation criteria as set out in the Persistence and Bioaccumulation Regulations. In addition, model data suggest that the substance may have a moderate to high potential for acute toxicity to aquatic organisms. Based on a comparison of predicted no-effect concentrations and estimated reasonable worst-case environmental exposure concentrations, it is concluded that Michler’s ketone 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.

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, Michler’s ketone meets one or more criteria set out in section 64 of CEPA 1999.

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

Publication of final decision after screening assessment of five substances 3H-Pyrazol-3-one, 4-[(2-chlorophenyl)azo]-2,4-dihydro-5-methyl-2-phenyl- (Pigment Yellow 60), CAS No. 6407-74-5; 3H-Pyrazol-3-one,4-[(2,4-dimethylphenyl)azo]-2,4-dihydro-5-methyl-2-phenyl- (Solvent Yellow 18), CAS No. 6407-78-9;1-Naphthalenemethanol, α,α-bis[4-(diethylamino)phenyl]-4-(ethylamino)- (Solvent Blue 5), CAS No. 1325-86-6; 1-Naphthalenemethanol, α,α-bis[4-(dimethylamino)phenyl]-4-(phenylamino)- (Solvent Blue 4), CAS No. 6786-83-0; and [1, 1-Biphenyl]-4,4′-diamine, N,N′-bis(2,4-dinitrophenyl)-3,3- dimethoxy- (Pigment Brown 22), CAS No. 29398-96-7 specified on the Domestic Substances List (subsection 77(6)of the Canadian Environmental Protection Act, 1999)

Whereas substances 3H-Pyrazol-3-one, 4-[(2-chlorophenyl) azo]-2,4-dihydro-5-methyl-2-phenyl- (Pigment Yellow 60), 3H-Pyrazol-3-one,4-[(2,4-dimethylphenyl)azo]-2,4-dihydro-5-methyl -2-phenyl- (Solvent Yellow 18), 1-Naphthalenemethanol, α,α-bis[4-(diethylamino)phenyl]-4-(ethylamino)- (Solvent Blue 5), 1-Naphthalenemethanol, α,α-bis[4-(dimethylamino)phenyl]-4-(phenylamino)- (Solvent Blue 4), and [1, 1′-Biphenyl]-4,4′-diamine, N,N-bis(2,4-dinitrophenyl)-3,3′- dimethoxy- (Pigment Brown 22) are substances 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 conducted on Pigment Yellow 60, Solvent Yellow 18, Solvent Blue 5, Solvent Blue 4, and Pigment Brown 22 pursuant to section 74 of the Act is annexed hereby;

Whereas the Ministers of the Environment and of Health have identified for the above-noted substances no manufacture or importation activity in a quantity above 100 kg per calendar year;

Whereas it concluded that Pigment Yellow 60, Solvent Yellow 18, Solvent Blue 5, Solvent Blue 4, and Pigment Brown 22 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-noted substances,

Notice therefore is hereby given that the Ministers of the Environment and of Health propose to take no further action on Pigment Yellow 60, Solvent Yellow 18, Solvent Blue 5, Solvent Blue 4, and Pigment Brown 22 at this time under section 77 of the Act.

JIM PRENTICE
Minister of the Environment
LEONA AGLUKKAQ
Minister of Health

ANNEX

Summary of the Final Screening Assessment of the five substances listed below conducted under section 74 of the Canadian Environmental Protection Act, 1999

CAS RN*

DSL Name

6407-74-5

3H-Pyrazol-3-one, 4-[(2-chlorophenyl)azo]-2,4-dihydro-5-methyl-2-phenyl-

6407-78-9

3H-Pyrazol-3-one, 4-[(2,4-dimethylphenyl)azo]-2,4-dihydro-5-methyl-2-phenyl-

1325-86-6

1-Naphthalenemethanol, α,α-bis[4-(diethylamino)phenyl]-4-(ethylamino)-

6786-83-0

1-Naphthalenemethanol, α,α-bis[4-(dimethylamino)phenyl]-4-(phenylamino)-

29398-96-7

[1, 1′-Biphenyl]-4,4′-diamine, N,N′-bis(2,4-dinitrophenyl)-3,3′-dimethoxy-

*CAS RN = Chemical Abstracts Service Registry Number

The above five substances on the Domestic Substances List (DSL) were identified as high priorities for screening assessment, to be part of the Challenge, because they met the ecological categorization criteria for persistence (P), 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. However, during categorization these substances were not identified as posing a high hazard to human health based on classifications by other national or international agencies for carcinogenicity, genotoxicity, developmental toxicity or reproductive toxicity.

Results from a notice issued under paragraph 71(1)(b) of CEPA 1999 in August 2008 revealed no reports of industrial activity (import or manufacture) with respect to these substances in Canada, equal or above the reporting threshold of 100 kg, for the 2006 reporting year. These results suggest that these substances are currently not in use above the specified reporting threshold, and therefore the likelihood of exposure humans or the environment to these substances in Canada resulting from commercial activity is low. Other sources of entry into the environment have not been identified at this time.

Information received as a result of the above notice issued under paragraph 71(1)(b) of CEPA 1999 and the accompanying questionnaire of August 2008 also revealed no significant new data relevant to the PBiT properties of these five 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 five 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.

While limited data and information on the five substances described above may suggest potential hazardous properties associated with these substances, exposure of the general population in Canada is expected to be low to negligible, and therefore the risk to human health is considered to be low. Confidence in the toxicity database is considered to be low.

Where relevant, research and monitoring will support verification of assumptions used during the screening assessment.

Conclusion

Based on available information, it is concluded that Pigment Yellow 60, Solvent Yellow 18, Solvent Blue 5, Solvent Blue 4, and Pigment Brown 22 do not meet the criteria set out in section 64 of CEPA 1999.

Because these substances are listed on the Domestic Substances List, their import and manufacture in Canada are not subject to notification under subsection 81(1) of CEPA 1999. Given the hazardous properties of these substances, there is concern that new activities that have not been identified or assessed could lead to these substances meeting the criteria set out in section 64 of the Act. Therefore, it is recommended to amend the DomesticSubstances List, under subsection 87(3) of the Act, to indicate that subsection 81(3) of the Act applies with respect to these substances so that new manufacture, import or use of these substances is subject to notification and undergo ecological and human health risk assessments.

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

Publication of final decision after screening assessment of a substance2-Cyclohexen-1-one, 3,5,5-trimethyl- (isophorone), CAS No.78-59-1 — specified on the Domestic Substances List (subsection 77(6) of the Canadian Environmental Protection Act, 1999)

Whereas 2-Cyclohexen-1-one, 3,5,5-trimethyl- (isophorone) 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 conducted on isophorone pursuant to section 74 of the Act is annexed hereby; and

Whereas it is concluded that isophorone 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 isophorone at this time under section 77 of the Act.

JIM PRENTICE
Minister of the Environment
LEONA AGLUKKAQ
Minister of Health

ANNEX

Summary of the Final Screening Assessment of 2-Cyclohexen1-one, 3,5,5-trimethyl- (isophorone)

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 2-Cyclohexen-1-one, 3,5,5-trimethyl- (isophorone), Chemical Abstracts Service Registry No. 78-59-1. The substance isophorone was identified in the categorization of the Domestic Substances List as a high priority for action under the Challenge. Isophorone was identified as a high priority as it was classified by the European Commission and the United States Environmental Protection Agency on the basis of carcinogenicity. The substance did not meet the ecological categorization criteria for persistence, bioaccumulation potential or inherent toxicity to aquatic organisms. Therefore, the focus of this assessment of isophorone relates primarily to human health risks.

According to information submitted under section 71 of CEPA 1999, isophorone was not manufactured by any company in Canada in the calendar year 2006. However, approximately 10 000–100 000 kg of the substance was imported in 2006, and approximately 1 000–10 000 kg was reported to be released to the atmosphere in the same year. The major use of isophorone is industrial. However, it was determined that, for the general population of Canada, the highest estimated exposure to isophorone would result from the use of isophorone as a food flavour.

Isophorone is used as a solvent for automotive and industrial coatings, including industrial metal coatings and food packaging, and in adhesives for plastics, polyvinyl chloride and polystyrene materials. Isophorone is used as a formulant in one registered pest control product in Canada, but the registration of this product was discontinued December 31, 2009.

As isophorone was classified on the basis of carcinogenicity by other national and international agencies, carcinogenicity was a key focus for this screening assessment. In long-term studies, rats showed some evidence of increased incidences of renal tubular cell adenomas and adenocarcinomas and of preputial gland carcinomas, whereas mice showed equivocal evidence of increased incidences of hepatocellular adenomas or carcinomas and of mesenchymal tumours in the integumentary system. However, the renal tumours induced by isophorone in rats involved a species-specific mechanism, the preputial gland tumours in rats were observed only at higher doses and the tumour incidence in mice were significantly increased only at higher doses. Consideration of the available information regarding genotoxicity and the conclusions of other agencies indicate that isophorone is not likely to be genotoxic. Accordingly, although the mode of induction of tumours is not fully elucidated, the tumours observed are not considered to have resulted from direct interaction with genetic material. Therefore, a threshold approach is used to assess risk to human health.

Non-neoplastic effects were observed in the kidneys of rats and in the liver of mice orally exposed to isophorone in repeated-dose studies. The margin between the highest upper-bounding estimate of exposure from food and beverages and critical effect levels is considered to be adequately protective to account for data gaps and uncertainties in the human health risk assessment for both cancer and non-cancer effects. Based on the available information on the potential to cause harm to human health and the resulting margin of exposure, it is concluded that isophorone is 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.

On the basis of the low ecological hazard posed by isophorone, as well as information on releases of isophorone to the environment, it is concluded that the 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. Isophorone does not meet the criteria for persistence or bioaccumulation as set out in the Persistence and Bioaccumulation Regulations.

This substance will be considered for inclusion in the 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 isophorone does not meet any of the criteria set out in section 64 of CEPA 1999.

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

Publication of final decision after screening assessment of a substance1,4-Dioxane,CAS No.123-91-1 — specified on the Domestic Substances List (subsection 77(6) of the Canadian Environmental Protection Act, 1999)

Whereas 1,4-dioxane 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 conducted on 1,4-dioxane pursuant to section 74 of the Act is annexed hereby; and

Whereas it is concluded that 1,4-dioxane 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 1,4-dioxane at this time under section 77 of the Act.

JIM PRENTICE
Minister of the Environment
LEONA AGLUKKAQ
Minister of Health

ANNEX

Summary of the Final Screening Assessment of 1,4-Dioxane

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 1,4-dioxane, Chemical Abstracts Service Registry No. 123-91-1. The substance 1,4-dioxane was identified in the categorization of the Domestic Substances List as a high priority for action under the Challenge. The substance 1,4-dioxane was identified as a high priority as it was considered to pose greatest potential for exposure of individuals in Canada and is classified by other agencies on the basis of carcinogenicity. Although this substance met the ecological categorization criteria for persistence, it did not meet the criteria for bioaccumulation and inherent toxicity to aquatic organisms. The focus of this assessment of 1,4-dioxane relates principally to human health risks.

According to information reported under section 71 of CEPA 1999, between 10 000 and 100 000 kg of 1,4-dioxane were both imported into and manufactured in Canada in 2006. In addition, Canadian companies reported using between 10 000 and 100 000 kg in that year. In terms of environmental releases, between 10 000 and 100 000 kg of 1,4-dioxane were released into the environment in 2006, with the majority entering water and air. In Canada, 1,4-dioxane is used primarily as a solvent for pharmaceutical processing and research and development, and as an analytical reagent for laboratory use. However, it is also found as an impurity in ethoxylated substances, which are used in numerous industries (manufacture of personal care products, detergents, food packaging, etc.).

Based on available information on concentrations in environmental media and results from a survey under section 71 of CEPA 1999, the general population is expected to be exposed to 1,4-dioxane from environmental media (ambient air, indoor air and drinking water), from food and during the use of consumer products (personal care and household products) containing this substance.

Based principally on the weight-of-evidence-based assessments of several international and other national agencies and available toxicological information, critical effects associated with exposure to 1,4-dioxane are tumorigenesis following oral and inhalation exposure, but not following dermal exposure; and other systemic effects, primarily liver and kidney damage, via all routes of exposure (i.e. oral, dermal and inhalation). The collective evidence indicates that 1,4-dioxane is not a mutagen and exhibits weak clastogenicity in some assays, but not others, at high exposure levels often associated with cytotoxicity. Consideration of the available information regarding genotoxicity, and conclusions of other agencies, indicate that 1,4-dioxane is not likely to be genotoxic. Accordingly, although the mode of induction of tumours is not fully elucidated, the tumours observed are not considered to have resulted from direct interaction with genetic material. Therefore, a threshold approach is used to characterize risk to human health.

The margins between upper-bounding estimates of exposure from environmental media and use of consumer products, taking into consideration multiple product use scenarios and levels associated with effects in experimental animals, are considered to be adequately protective to account for uncertainties in the human health risk assessment for both cancer and non-cancer effects.

On the basis of the adequacy of the margins between conservative estimates of exposure to 1,4-dioxane and critical effect levels in experimental animals, it is concluded that 1,4-dioxane 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.

Based on available empirical data, 1,4-dioxane is expected to degrade only in air, but not in water, soil or sediment. It is not expected to bioaccumulate in organisms. The substance meets the persistence criteria but not the bioaccumulation criteria set out in the Persistence and Bioaccumulation Regulations. In addition, empirical aquatic toxicity data indicate that the substance poses a low hazard to aquatic organisms. Based on a comparison of a predicted no-effect concentration with an estimated reasonable worst-case environmental exposure concentration for Canadian surface water, it is concluded that 1,4-dioxane 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 considered for inclusion 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 1,4-dioxane does not meet any of the criteria set out in section 64 of CEPA 1999.

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

Publication of final decision after screening assessment of a substance — Methanesulfonamide, N-[2-[(2,6-dicyano-4-methylphenyl)azo]-5-(dipropylamino)phenyl]-, CAS No. 72968-82-2 — specified on the Domestic Substances List (subsection 77(6) of the Canadian Environmental Protection Act, 1999)

Whereas Methanesulfonamide, N-[2-[(2,6-dicyano-4-methylphenyl)azo]-5-(dipropylamino)phenyl]- 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 conducted on Methanesulfonamide, N-[2-[(2,6-dicyano-4-methylphenyl)azo]-5-(dipropylamino)phenyl]- pursuant to section 74 of the Act is annexed hereby; and

Whereas it is concluded that Methanesulfonamide, N-[2-[(2,6dicyano-4-methylphenyl)azo]-5-(dipropylamino)phenyl]- 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 Methanesulfonamide, N-[2-[(2,6-dicyano-4-methylphenyl)azo]-5-(dipropylamino)phenyl]- at this time under section 77 of the Act.

JIM PRENTICE
Minister of the Environment
LEONA AGLUKKAQ
Minister of Health

ANNEX

Summary of the Final Screening Assessment of Methanesulfonamide, N-[2-[(2,6-dicyano-4methylphenyl)azo]-5-(dipropylamino)phenyl]-

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 Methanesulfonamide, N-[2-[(2,6-dicyano-4-methylphenyl)azo]-5-(dipropylamino)phenyl]- (DADM), Chemical Abstracts Service Registry No. 72968-82-2. This substance was identified as a high priority for screening assessment and included in the Challenge because it had been found to meet the ecological categorization criteria for persistence, bioaccumulation and inherent toxicity to non-human organisms and was believed to be in commerce in Canada.

The substance DADM was not considered to be a high priority for assessment of potential risks to human health, based on application of the simple exposure and hazard tools developed by Health Canada for categorization of substances on the Domestic Substances List.

The substance was previously used in Canada as a dye and a printing ink based on use codes from the 1986 Domestic Substances List. It is not naturally produced in the environment. No companies reported manufacturing, importing or using this substance in Canada above the reporting thresholds in 2006; however, four companies did have a stakeholder interest in the substance. In the assessment, the reporting threshold of 100 kg was used to build scenarios and capture the highest potential quantity of DADM in use in Canada.

Based on reported use patterns and certain assumptions, most of DADM would be expected to end up in solid waste disposal sites, and a significant proportion may be released to sewer water (17.1%). The substance is not expected to be soluble in water; instead, it is expected to partition to particles because of its hydrophobic nature. For these reasons, after release to water, DADM would likely end up mostly in sediments. It is not expected to be volatile, hence it is neither significantly present in air nor subject to long-range atmospheric transport.

Based on prediction of its physical and chemical properties, DADM is expected to degrade slowly under aerobic conditions in the environment (in water, sediment and soil). Because of the lack of experimental data relating to bioaccumulation potential, new data for an analogue of the substance were used in the assessment. This resulted in the prediction that the substance has a low potential for bioaccumulation in the environment. DADM is therefore concluded to meet the persistence criteria but does not meet the bioaccumulation criteria as set out in the Persistence and Bioaccumulation Regulations. In addition, experimental toxicity data for DADM and chemical analogues suggest that the substance has a low to moderate potential to cause acute harm to aquatic organisms.

For this screening assessment, two very conservative exposure scenarios were selected representing industrial and consumer use-related releases to the aquatic environment. The first scenario simulated discharge of DADM to the aquatic environment following use of the dye by an industrial operation. The second scenario simulated the release of DADM to the aquatic environment due to consumer use (in this case, washing of dyed clothing). The predicted environmental concentrations (PECs) in water were well below the predicted no-effect concentrations (PNECs) calculated for sensitive aquatic species.

Based on the results of a survey under section 71 of CEPA 1999, DADM is not manufactured in or imported into Canada in quantities above the reporting threshold of 100 kg. Therefore, exposure of the general population in Canada to this substance is considered to be low. Although there may be potential hazards associated with this substance, based on the available information, the potential risk to human health is considered to be low due to low exposure of the general population of Canada.

Because this substance is listed on the Domestic Substances List, its import and manufacture in Canada are not subject to notification under subsection 81(1) of CEPA 1999. Given the potential hazardous properties of this substance, there is concern that new activities that have not been identified or assessed could lead to this substance meeting the criteria set out in section 64 of the Act. Therefore, it is recommended that the Domestic Substances List be amended, under subsection 87(3) of the Act, to indicate that subsection 81(3) of the Act applies with respect to this substance so that new manufacture, import or use of this substance be subject to notification and undergo ecological and human health risk assessments.

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 DADM does not meet any of the criteria set out in section 64 of CEPA 1999.

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

Publication of final decision after screening assessment of a substance — Benzoic acid, 2,3,4,5-tetrachloro-6-cyano-, methyl ester, reaction products with 4-[(4-aminophenyl)azo]-3-methylbenzenamine and sodium methoxide, CAS No. 106276-78-2 — specified on the Domestic Substances List (subsection 77(6) of the Canadian Environmental Protection Act, 1999)

Whereas Benzoic acid, 2,3,4,5-tetrachloro-6-cyano-, methyl ester, reaction products with 4-[(4-aminophenyl)azo]-3methylbenzenamine and sodium methoxide 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 conducted on Benzoic acid, 2,3,4,5-tetrachloro-6-cyano-, methyl ester, reaction products with 4-[(4-aminophenyl)azo]-3methylbenzenamine and sodium methoxide pursuant to section 74 of the Act is annexed hereby; and

Whereas it is concluded that Benzoic acid, 2,3,4,5-tetrachloro-6-cyano-, methyl ester, reaction products with 4-[(4-aminophenyl)azo]-3-methylbenzenamine and sodium methoxide 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 Benzoic acid, 2,3,4,5-tetrachloro-6-cyano-, methyl ester, reaction products with 4-[(4-aminophenyl)azo]-3-methylbenzenamine and sodium methoxide at this time under section 77 of the Act.

JIM PRENTICE
Minister of the Environment
LEONA AGLUKKAQ
Minister of Health

ANNEX

Summary of the Final Screening Assessment on Benzoic acid, 2,3,4,5-tetrachloro-6-cyano-, methyl ester, reaction products with 4-[(4-aminophenyl)azo]-3-methylbenzenamine and sodium methoxide

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 Benzoic acid, 2,3,4,5-tetrachloro-6-cyano-, methyl ester, reaction products with 4-[(4-aminophenyl)azo]-3-methylbenzenamine and sodium methoxide (MATCB), Chemical Abstracts Service Registry No. 106276-78-2. This substance was identified as a high priority for screening assessment and included in the Challenge because it had been found to meet the ecological categorization criteria for persistence, bioaccumulation and inherent toxicity to non-human organisms and is believed to be in commerce in Canada.

The substance MATCB was not considered to be a high priority for assessment of potential risks to human health, based on 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 principally on information relevant to the evaluation of ecological risks.

MATCB is an Unknown or Variable Composition, Complex Reaction Products, or Biological Materials (UVCB) and used in Canada primarily as a textile dye. The substance is not naturally produced in the environment. It is not reported to be manufactured in Canada; however, between 100 and 1 000 kg of the substance were imported within dyed raw materials into Canada in 2006.

Based on reported use patterns and certain assumptions, most of MATCB is expected to end up in solid waste disposal sites (90%), and the residue proportion is estimated to be released to sewer water (10%). The substance is not expected to be soluble in water or to be volatile; instead, it is expected to partition to particles because of its hydrophobic nature. For these reasons, after release to water, the substance will likely end up mostly in sediments and, to a lesser extent, in agricultural soil that has been amended with biosolids. It is not expected to be significantly present in air, hence it is not expected to be subject to long-range atmospheric transport.

Based on prediction of its physical and chemical properties, MATCB is expected to degrade slowly under aerobic conditions in the environment (in water, sediment and soil). Due to lack of experimental data relating to the bioaccumulation potential, an experimental value adjustment (EVA) method and new data for an analogue of MATCB were used in the assessment. This resulted in the prediction that MATCB has a low potential for bioaccumulation in the environment. The substance therefore meets the persistence criteria but does not meet the bioaccumulation criteria as set out in the Persistence and Bioaccumulation Regulations. In addition, experimental toxicity data for chemical analogues suggest that MATCB has a low to moderate potential to cause acute harm to aquatic organisms.

For this screening assessment, a very conservative exposure scenario was selected representing consumer use-related releases to the aquatic environment. The scenario simulated discharge of MATCB to the aquatic environment due to the washing of dyed clothing. The predicted environmental concentrations (PECs) in water were well below the predicted no-effect concentrations (PNECs) calculated for sensitive aquatic species. Therefore, it is concluded that the 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 potential for exposure of the general population in Canada to MATCB from environmental media is expected to be negligible. Exposure of the general population in Canada to MATCB from consumer products is expected to be low given the intended purpose of the product (dyes in synthetic textiles), taking into consideration potential for incidental exposures, such as mouthing by toddlers. Due to the lack of experimental data on MATCB, upper-bounding exposure estimates were derived based on available data on the migration of disperse dyes from synthetic textiles.

No empirical health effects data were identified for MATCB. The outputs of Quantitative Structure-Activity Relationship (QSAR) predictions for genotoxicity and carcinogenicity were mixed. Information from analogues and potential MATCB metabolites suggests a potential hazard for genotoxicity endpoints.

Although limited data may suggest a potential hazard associated with MATCB, exposure of the general population in Canada based on the use of the substance in textiles is expected to be low, therefore the risk to human health is considered to be low.

Because this substance is listed on the Domestic Substances List, its import and manufacture in Canada are not subject to notification under subsection 81(1) of the Act. Given the potential hazardous properties of this substance, there is concern that new activities that have not been identified or assessed could lead to this substance meeting the criteria set out in section 64 of the Act. Therefore, it is recommended to amend the Domestic Substances List, under subsection 87(3) of the Act, to indicate that subsection 81(3) of the Act applies with respect to the substance so that new manufacture, import or use of this substance be subject to notification and undergo ecological and human health risk assessments.

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 Benzoic acid, 2,3,4,5-tetrachloro-6-cyano-, methyl ester, reaction products with 4-[(4-aminophenyl)azo]-3-methylbenzenamine and sodium methoxide does not meet any of the criteria set out in section 64 of CEPA 1999.

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

Publication of final decision after screening assessment of two substances — Propanenitrile, 3-[ethyl[3-methyl-4-[(6-nitro-2-benzothiazolyl)azo]phenyl]amino]- (Disperse Red 179), CAS No. 16586-42-8 and Propanenitrile, 3-[[4-[(5,6-dichloro-2-benzothiazolyl)azo]phenyl]ethylamino]- (DAPEP), CAS No. 25176-89-0 — specified on the Domestic Substances List (subsection 77(6) of the Canadian Environmental Protection Act, 1999)

Whereas Propanenitrile, 3-[ethyl[3-methyl-4-[(6-nitro-2-benzothiazolyl)azo]phenyl]amino]- (Disperse Red 179) and Propanenitrile, 3-[[4-[(5,6-dichloro-2-benzothiazolyl)azo]phenyl] ethylamino]- are substances 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 conducted on Disperse Red 179 and Propanenitrile, 3-[[4-[(5,6-dichloro-2-benzothiazolyl)azo]phenyl]ethylamino]- pursuant to section 74 of the Act is annexed hereby; and

Whereas it is concluded that Disperse Red 179 and Propanenitrile, 3-[[4-[(5,6-dichloro-2-benzothiazolyl)azo]phenyl] ethylamino]- do 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 Disperse Red 179 and Propanenitrile, 3-[[4-[(5,6-dichloro-2-benzothiazolyl)azo]phenyl]ethylamino]- at this time under sec-tion 77 of the Act.

JIM PRENTICE
Minister of the Environment
LEONA AGLUKKAQ
Minister of Health

ANNEX

Summary of the Final Screening Assessment of Propanenitrile, 3-[ethyl[3-methyl-4-[(6-nitro-2-benzothiazolyl)azo]phenyl]amino]- (Disperse Red 179) and Propanenitrile, 3-[[4-[(5,6-dichloro-2-benzothiazolyl)azo]phenyl]ethylamino]-

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 Propanenitrile, 3-[ethyl[3-methyl-4-[(6-nitro-2-benzothiazolyl)azo] phenyl]amino]- (Disperse Red 179), Chemical Abstracts Service Registry No. 16586-42-8 and Propanenitrile, 3-[[4-[(5,6-dichloro-2-benzothiazolyl)azo]phenyl]ethylamino]- (DAPEP), Chemical Abstracts Service Registry No. 25176-89-0. These substances were identified as high priorities for screening assessment and included in the Challenge because they had been found to meet the ecological categorization criteria for persistence, bioaccumulation potential and inherent toxicity to non-human organisms and are believed to be in commerce in Canada.

The substances Disperse Red 179 and DAPEP were not considered to be high priorities for assessment of potential risks to human health, based on 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 principally on information relevant to the evaluation of ecological risks.

Disperse Red 179 and DAPEP are organic substances that are used in Canada primarily as red dyeing agents for synthetic fibres for clothing and home textile uses. Due to their similar structure and uses, Disperse Red 179 and DAPEP are being assessed together in this report. These substances are not naturally produced in the environment. They are not reported to be manufactured in Canada above the reporting threshold of 100 kg/year; however, 400 kg of Disperse Red 179 and 100 kg of DAPEP were imported into the country in 2006 for use in the textile industry.

Based on certain assumptions and reported use patterns in Canada, the greatest proportion of these substances is expected to end up in waste disposal sites. About 17% of Disperse Red 179 and DAPEP is estimated to be released to water, and no releases are predicted to air and soil. Disperse Red 179 and DAPEP present very low solubility in water and octanol (based on analogue and modelled data). Disperse Red 179 and DAPEP are present in the environment primarily as fine particulate matter that is not volatile, are chemically stable, and have a tendency to partition by gravity to sediments if released to surface waters, and would likely partition to soils if released to air.

Based on their physical and chemical properties and on experimental biodegradation test data, Disperse Red 179 and DAPEP are expected to be persistent in the environment in all media under aerobic conditions. Newly identified analogue experimental data and expert judgement indicate that these dyes have a low potential to accumulate in the lipid tissues of organisms. The substances therefore meet the persistence criteria but do not meet the bioaccumulation criteria as set out in the Persistence and Bioaccumulation Regulations. In addition, new experimental toxicity data for chemical analogues suggest that these substances have at most a low to moderate potential to cause acute harm to aquatic organisms.

For the environmental section of this screening assessment, two very conservative exposure scenarios representing releases from industrial and consumer use to the aquatic environment were applied. The first scenario simulated discharge of Disperse Red 179 or DAPEP to the aquatic environment following use of each dye by an industrial operation. The second scenario simulated the release of Disperse Red 179 or DAPEP to the aquatic environment from consumer use (such as washing laundry). The predicted environmental concentrations in water for each scenario were below the predicted no-effect concentrations calculated for pelagic organisms.

The potential for exposure of the general population to Disperse Red 179 and DAPEP from environmental media is expected to be negligible. Exposure to Disperse Red 179 and DAPEP from consumer products is expected to be low given the intended purpose of the product (dyes in synthetic textiles), taking into consideration potential for incidental exposures, such as mouthing by toddlers. Due to the lack of experimental data on these substances, upper-bounding exposure estimates were derived based on available data on the migration of disperse dyes from synthetic textiles.

The limited empirical data identified for Disperse Red 179 and DAPEP, potential metabolites, and analogues, together with mixed Quantitative Structure-Activity Relationship (QSAR) predictions, suggest these substances may pose a potential hazard to human health.

Although limited data may suggest a potential hazard associated with Disperse Red 179 and DAPEP, exposure of the general population in Canada based on the use of the substances in textiles is expected to be low; therefore, the risk to human health is considered to be low.

Because these substances are listed on the Domestic Substances List, their import and manufacture in Canada are not subject to notification under subsection 81(1) of CEPA 1999. Given the potential hazardous properties of these substances, there is concern that new activities that have not been identified or assessed could lead to these substances meeting the criteria set out in section 64 of the Act. Therefore, it is recommended to amend the Domestic Substances List, under subsection 87(3) of the Act, to indicate that subsection 81(3) of the Act applies with respect to these substances so that new manufacture, import or use of these substances be subject to notification and undergo ecological and human health risk assessments.

In addition and where relevant, research and monitoring will support verification of assumptions used during the screening assessment.

Conclusion

Based on the information available, Disperse Red 179 and DAPEP do not meet any of the criteria set out in section 64 of CEPA 1999.

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