Vol. 143, No. 36 — September 5, 2009

DEPARTMENT OF THE ENVIRONMENT

DEPARTMENT OF HEALTH

CANADIAN ENVIRONMENTAL PROTECTION ACT, 1999

Publication 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. 106276-78-2
CAS No. 123-91-1
CAS No. 16586-42-8
CAS No. 25176-89-0
CAS No. 72968-82-2

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)- (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 draft Screening Assessment conducted on n-butyl glycidyl ether pursuant to paragraph 68(b) of the Canadian Environmental Protection Act, 1999 is annexed hereby; and

Whereas it is proposed to conclude that 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 have released a risk management scope document for this substance to initiate discussions with stakeholders on the development of a risk management approach.

Public comment period

As specified under subsection 77(5) of the Canadian Environmental Protection Act, 1999, any person may, within 60 days after publication of this notice, file with the Minister of the Environment written comments on the measure the Ministers propose to take and on the scientific considerations on the basis of which the measure is proposed. More information regarding the scientific considerations 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.

GEORGE ENEI
Acting Director General
Science and Risk Assessment Directorate
On behalf of the Minister of the Environment

MARGARET KENNY
Director General
Chemical Sectors Directorate
On behalf of the Minister of the Environment

KAREN LLOYD
Director General
Safe Environments Directorate
On behalf of the Minister of Health

ANNEX

Summary of the Screening Assessment on 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 substance of intermediate potential for exposure to individuals in Canada and has been classified by other agencies on the basis of carcinogenicity and genotoxicity. Since n-butyl glycidyl ether did not meet the criteria for persistence, bioaccumulation or inherent toxicity to aquatic organisms, the focus of this assessment relates 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 to 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, a chemical intermediate and as an acid acceptor for stabilizing chlorinated solvents. In Canada, n-butyl glycidyl ether is mainly used in epoxy resin formulations which have applications in coatings, adhesives, binders, sealants, fillers and resins.

Emissions of n-butyl glycidyl ether into the ambient environment would likely come from anthropogenic sources, specifically from the commercial production and use of epoxy resins. Based on reported releases, uses and physical-chemical properties, the principal route of exposure for the general population will likely be through inhalation of air; exposure 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 therefore does not meet the persistence criterion or the bioaccumulation criterion as set out in the Persistence and Bioaccumulation Regulations. In addition, modelled 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 estimated reasonable worst-case environmental exposure concentrations, it is considered unlikely that n-butyl glycidyl ether is causing ecological harm in Canada.

Although no long-term carcinogenicity assays have been conducted with n-butyl glycidyl ether, it was genotoxic in several in vivo and in vitro assays. In addition, substances which 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 proposed to conclude 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 proposed to conclude 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.

Proposed conclusion

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

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

Publication after screening assessment of a substance — 2-Butanone, oxime (butanone oxime), CAS No.96-29-7 — specified on the Domestic Substances List (subsection 77(1) 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 draft Screening Assessment conducted on butanone oxime pursuant to section 74 of the Act is annexed hereby; and

Whereas it is proposed to conclude that 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 have released a risk management scope document for this substance to initiate discussions with stakeholders on the development of a risk management approach.

Public comment period

As specified under subsection 77(5) of the Canadian Environmental Protection Act, 1999, any person may, within 60 days after publication of this notice, file with the Minister of the Environment written comments on the measure the Ministers propose to take and on the scientific considerations on the basis of which the measure is proposed. More information regarding the scientific considerations 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.

GEORGE ENEI
Acting Director General
Science and Risk Assessment Directorate
On behalf of the Minister of the Environment

MARGARET KENNY
Director General
Chemical Sectors Directorate
On behalf of the Minister of the Environment

KAREN LLOYD
Director General
Safe Environments Directorate
On behalf of the 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 Challenge. Butanone oxime 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 the European Commission on the basis of carcinogenicity. Although butanone oxime met the ecological categorization criterion for persistence, it did not meet the criteria for potential for bioaccumulation and inherent toxicity to aquatic organisms. Therefore, the focus of this assessment of butanone oxime relates 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, namely 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 use of butanone oxime amounted to quantities of nearly 120 000 kg in the same reporting year. There is significantly little data regarding the release and fate of butanone oxime in environmental media in Canada, and worldwide. Butanone oxime is not a naturally occurring substance; thus, releases of the substance to the environment is 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 only seen at mid- and/or high concentrations of butanone oxime. The results from the in vivo and in vitro genotoxicity assays demonstrates the absence of mutagenicity. It appears that chronic exposure to butanone oxime induces tumours by a mechanism that does not involve direct interaction with genetic material.

Non-neoplastic effects were also observed in the nasal cavity of rats and/or mice in inhalation studies of short-term through to chronic exposure. Also, repeated dose studies based on oral exposure showed effects in the spleen, liver and kidney of rats as well as haematological effects in both rats and rabbits. Based on comparison of estimated exposures to butanone oxime in Canada with the critical effect level for non-cancer effects, 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.

On the basis of the carcinogenicity of butanone oxime, for which there is limited evidence of threshold mechanisms, as well as the potential inadequacy of the margins between estimated exposures to butanone oxime and critical effect levels, it is proposed to conclude 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 reported releases of butanone oxime, it is proposed to conclude 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 criterion for persistence but does not meet the criterion for bioaccumulation potential as set out in the Persistence and Bioaccumulation Regulations (Canada 2000).

Proposed conclusion

Based on the information available, it is proposed to conclude that butanone oxime meets one or more criteria set out in section 64 of CEPA 1999.

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

Publication after screening assessment of a substance — Methanone, bis[4-(dimethylamino)phenyl]- (Michler’s ketone), CAS No. 90-94-8 — specified on the Domestic Substances List (subsection 77(1) 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 draft Screening Assessment conducted on Michler’s ketone pursuant to section 74 of the Act is annexed hereby; and

Whereas it is proposed to conclude that 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 have released a risk management scope document for this substance to initiate discussions with stakeholders on the development of a risk management approach.

Public comment period

As specified under subsection 77(5) of the Canadian Environmental Protection Act, 1999, any person may, within 60 days after publication of this notice, file with the Minister of the Environment written comments on the measure the Ministers propose to take and on the scientific considerations on the basis of which the measure is proposed. More information regarding the scientific considerations 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.

GEORGE ENEI
Acting Director General
Science and Risk Assessment Directorate
On behalf of the Minister of the Environment

MARGARET KENNY
Director General
Chemical Sectors Directorate
On behalf of the Minister of the Environment

KAREN LLOYD
Director General
Safe Environments Directorate
On behalf of the 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 Substances List 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 U.S. National Toxicology Program on the basis of carcinogenicity. The substance did meet 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. In 2006, 667 kg of Michler’s ketone were imported into Canada, whereas no manufacturing was reported in Canada in 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 type of use 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 upon 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 the 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 likely to have resulted from direct interaction with genetic material.

The reported 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 proposed to conclude 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, modelled acute aquatic toxicity data suggest that the substance poses a low to moderate risk to aquatic organisms. Based on a comparison of predicted no-effect concentrations and estimated reasonable worst-case environmental exposure concentrations, it is considered unlikely that Michler’s ketone is causing ecological harm in Canada.

This substance will be included 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.

Proposed conclusion

Based on the information available, it is proposed to conclude that Michler’s ketone meets one or more criteria set out in section 64 of CEPA 1999.

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

Publication 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(1)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 a draft 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 is proposed to conclude 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.

Public comment period

As specified under subsection 77(5) of the Canadian Environmental Protection Act, 1999, any person may, within 60 days after publication of this notice, file with the Minister of the Environment written comments on the measure the Ministers propose to take and on the scientific considerations on the basis of which the measure is proposed. More information regarding the scientific considerations 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.

GEORGE ENEI
Acting Director General
Science and Risk Assessment Directorate
On behalf of the Minister of the Environment

MARGARET KENNY
Director General
Chemical Sectors Directorate
On behalf of the Minister of the Environment

KAREN LLOYD
Director General
Safe Environments Directorate
On behalf of the Minister of Health

ANNEX

Summary of the Draft 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) 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 five substances.

Results from notices issued under paragraph 71(1)(b) of CEPA 1999 in March 2006 and 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 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.

Information received as a result of the above notices 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.

Proposed conclusion

Based on available information, and until new information is received indicating that any of these substances is entering, or may enter, the environment, it is proposed to conclude that the above five substances are currently not entering, nor are they likely to enter, the environment as a result of commercial activity in Canada. Therefore, it is proposed to conclude that they do not meet the criteria set out in section 64 of CEPA 1999.

As substances listed on the DSL, import and manufacture of these five 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 five 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 five 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 after screening assessment of a substance — 2-Cyclohexen-1-one, 3,5,5-trimethyl- (isophorone), CAS No.78-59-1 — specified on the Domestic Substances List (subsection 77(1) 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 draft Screening Assessment conducted on isophorone pursuant to section 74 of the Act is annexed hereby; and

Whereas it is proposed to conclude 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.

Public comment period

As specified under subsection 77(5) of the Canadian Environmental Protection Act, 1999, any person may, within 60 days after publication of this notice, file with the Minister of the Environment written comments on the measure the Ministers propose to take and on the scientific considerations on the basis of which the measure is proposed. More information regarding the scientific considerations 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.

GEORGE ENEI
Acting Director General
Science and Risk Assessment Directorate
On behalf of the Minister of the Environment

MARGARET KENNY
Director General
Chemical Sectors Directorate
On behalf of the Minister of the Environment

KAREN LLOYD
Director General
Safe Environments Directorate
On behalf of the Minister of Health

ANNEX

Summary of the Screening Assessment of 2-Cyclohexen-1-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 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 U.S. 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 to human health risks.

Isophorone is used as a solvent for auto and industrial coatings and as a solvent carrier in industrial metal coatings and in food packaging, and as an adhesive for plastics, polyvinyl chloride and polystyrene materials. It may be used as a chemical intermediate in organic chemical syntheses and is also permitted as an acceptable flavour enhancer in natural health products. It is possible that isophorone is used as a flavour in foods sold in Canada. Isophorone is used as a formulant in one registered pesticide in Canada but is to be discontinued as of December 31, 2009. In the United States, isophorone is registered as an inert ingredient in some pesticides applied to rice and certain vegetables.

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 7 000 kg was reported to be released to the atmosphere. The major use of isophorone is industrial, with the principal source of exposure to the general population thought to be through food and beverages.

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 incidence of hepatocellular adenomas or carcinomas and of mesenchymal tumours in the integumentary system. The available data indicates that isophorone is not genotoxic and is not likely to react with DNA.

Non-neoplastic effects based on oral exposure in repeated dose studies were observed in the kidneys of rats and in the liver of mice. The margin between the critical effect level and the maximum estimated exposure to isophorone in Canada is considered adequately protective of human health. Based on the available information on the potential to cause harm to human health and the resulting margin of exposure for non-neoplastic effects, it is proposed to conclude 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.

It is therefore proposed to conclude that isophorone does not meet the definition of toxic as set out in section 64 of CEPA 1999.

On the basis of its low ecological hazard and reported releases of isophorone, it is proposed to conclude that isophorone 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.

Proposed conclusion

Based on the information available, it is proposed to conclude that isophorone does not meet any of the criteria set out in section 64 of CEPA 1999.

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

Publication 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 (MATCB), CAS No. 106276-78-2 — specified on the Domestic Substances List (subsection 77(1) 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]-3-methylbenzenamine and sodium methoxide (MATCB) 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 draft Screening Assessment conducted on MATCB pursuant to section 74 of the Act is annexed hereby; and

Whereas it is proposed to conclude that MATCB 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 MATCB at this time under section 77 of the Act.

Public comment period

As specified under subsection 77(5) of the Canadian Environmental Protection Act, 1999, any person may, within 60 days after publication of this notice, file with the Minister of the Environment written comments on the measure the Ministers propose to take and on the scientific considerations on the basis of which the measure is proposed. More information regarding the scientific considerations 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.

GEORGE ENEI
Acting Director General
Science and Risk Assessment Directorate
On behalf of the Minister of the Environment

MARGARET KENNY
Director General
Chemical Sectors Directorate
On behalf of the Minister of the Environment

KAREN LLOYD
Director General
Safe Environments Directorate
On behalf of the Minister of Health

ANNEX

Summary of the 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)

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 potential 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 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.

MATCB is a part of Unknown or Variable Composition, Complex Reaction Products, or Biological Materials (UVCBs) that are used in Canada primarily as a colour dye in textiles. MATCB 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 for use in the textile industry.

Based on reported use patterns and certain assumptions, most of MATCB is expected to end up in solid waste disposal sites, and a significant 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.

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 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 conservative exposure scenario representing consumer use releases to the aquatic environment was developed. The scenario simulated discharge of MATCB to the aquatic environment due to washing of dyed clothing. The predicted environmental concentrations in water (PECs) were well below the predicted no-effect concentration (PNEC) calculated for sensitive aquatic species.

Based on the information available, MATCB does not meet any of the criteria set out in section 64 of the CEPA 1999.

This substance will be included 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.

Proposed conclusion

Based on the information available, it is proposed to conclude that MATCB does not meet any of the criteria set out in section 64 of CEPA 1999.

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

Publication after screening assessment of a substance — 1,4-Dioxane, CAS No. 123-91-1 — specified on the Domestic Substances List (subsection 77(1) 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 draft Screening Assessment conducted on 1,4-dioxane pursuant to section 74 of the Act is annexed hereby; and

Whereas it is proposed to conclude 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.

Public comment period

As specified under subsection 77(5) of the Canadian Environmental Protection Act, 1999, any person may, within 60 days after publication of this notice, file with the Minister of the Environment written comments on the measure the Ministers propose to take and on the scientific considerations on the basis of which the measure is proposed. More information regarding the scientific considerations 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.

GEORGE ENEI
Acting Director General
Science and Risk Assessment Directorate
On behalf of the Minister of the Environment

MARGARET KENNY
Director General
Chemical Sectors Directorate
On behalf of the Minister of the Environment

KAREN LLOYD
Director General
Safe Environments Directorate
On behalf of the Minister of Health

ANNEX

Summary of the 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 on 1,4-dioxane, Chemical Abstracts Service Registry No. 123-91-1. During the categorization process, this substance was identified as a high priority for screening assessment and included in the Challenge because it had been considered to pose “greatest potential for exposure” to individuals in Canada and has been classified by other agencies on the basis of carcinogenicity. The substance did not meet the ecological categorization criteria for persistence, bioaccumulation potential, and inherent toxicity to aquatic organisms. Therefore, 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, amounts between 10 000 and 100 000 kg of 1,4-dioxane were both imported and manufactured in Canada in 2006. In addition, Canadian companies reported using between 10 000 and 100 000 kg. 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 primarily used as a solvent in research and development. However it is also found as an impurity in ethoxylated substances which are used in numerous industries (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 exposure to 1,4-dioxane is expected to be from the environmental media (ambient air, indoor air, food and drinking water) 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 agencies and available toxicological information, critical effects associated with exposure to 1,4-dioxane are tumourigenesis following oral exposure, but not dermal or inhalation 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 at high exposure levels in some assays, but not others, often associated with cytotoxity. Based on available toxicological as well as toxicokinetics and toxicodynamics information, a threshold approach is used to assess risk to human health. A practical no-observed-adverse-effect-level (NOAEL) for chronic adverse effects, as well as the level at which no tumours were observed, has been identified in rats exposed to 1,4-dioxane in drinking water for two years.

The margins between upper-bounding estimates of exposure from environmental media and use of consumer products, taking into consideration frequencies and patterns of use as well as exposure aggregation, and levels associated with effects in experimental animals are considered to be adequately protective to account for data gaps and uncertainties in the human health risk assessment.

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 proposed to conclude 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 (not in water, soil or sediment). It is not expected to bioaccumulate in the environment. The substance therefore 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 toxic effect concentration and an estimated reasonable worst case environmental exposure concentration for Canadian surface water, it is considered unlikely that 1,4-dioxane is causing ecological harm in Canada.

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.

Proposed conclusion

Based on the information available, it is proposed to conclude that 1,4-dioxane does not meet any of the criteria set out in section 64 of CEPA 1999.

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

Publication after screening assessment of two substances — Propanenitrile, 3-[ethyl[3-methyl-4-[(6-nitro2-benzothiazolyl)azo]phenyl]amino]- (Disperse Red 179), CAS No. 16586-42-8 and Propanenitrile, 3-[[4-[(5,6-dichloro2-benzothiazolyl)azo]phenyl]ethylamino]- (DAPEP), CAS No. 25176-89-0 — specified on the Domestic Substances List (subsection 77(1) of the Canadian Environmental Protection Act, 1999)

Whereas Propanenitrile, 3-[ethyl [3-methyl-4-[(6-nitro2-benzothiazolyl)azo]phenyl]amino]- (Disperse Red 179) and Propanenitrile, 3-[[4-[(5,6-dichloro-2-benzothiazolyl)azo]phenyl] ethylamino]- (DAPEP) are substances on the Domestic Substances List identified under subsection 73(1) of the Canadian Environmental Protection Act, 1999;

Whereas a summary of the draft Screening Assessment conducted on Disperse Red 179 and DAPEP pursuant to section 74 of the Act is annexed hereby; and

Whereas it is proposed to conclude that Disperse Red 179 and DAPEP 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 DAPEP at this time under section 77 of the Act.

Public comment period

As specified under subsection 77(5) of the Canadian Environmental Protection Act, 1999, any person may, within 60 days after publication of this notice, file with the Minister of the Environment written comments on the measure the Ministers propose to take and on the scientific considerations on the basis of which the measure is proposed. More information regarding the scientific considerations 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.

GEORGE ENEI
Acting Director General
Science and Risk Assessment Directorate
On behalf of the Minister of the Environment

MARGARET KENNY
Director General
Chemical Sectors Directorate
On behalf of the Minister of the Environment

KAREN LLOYD
Director General
Safe Environments Directorate
On behalf of the Minister of Health

ANNEX

Summary of the Screening Assessment on 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]- (DAPEP)

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 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.

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 assessed together in this report. These substances are not naturally produced in the environment. They are not reported to be manufactured in Canada; 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, most of these substances are 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 rather chemically stable, and have a tendency to partition by gravity to sediments if released to surface waters, and would likely partition to soils if ever 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. However, newly identified analogue experimental data, modelled 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 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.

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.

These substances will be included 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.

Proposed conclusion

Based on the information available, it is proposed to conclude that Disperse Red 179 and DAPEP do not meet the criteria set out in section 64 of CEPA 1999.

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

Publication after screening assessment of a substance — Methanesulfonamide, N-[2-[(2,6-dicyano-4-methylphenyl)azo]-5-(dipropylamino)phenyl]-(DADM), CAS No. 72968-82-2 — specified on the Domestic Substances List (subsection 77(1) of the Canadian Environmental Protection Act, 1999)

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

Whereas it is proposed to conclude that DADM 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 DADM at this time under section 77 of the Act.

Public comment period

As specified under subsection 77(5) of the Canadian Environmental Protection Act, 1999, any person may, within 60 days after publication of this notice, file with the Minister of the Environment written comments on the measure the Ministers propose to take and on the scientific considerations on the basis of which the measure is proposed. More information regarding the scientific considerations 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.

GEORGE ENEI
Acting Director General
Science and Risk Assessment Directorate
On behalf of the Minister of the Environment

MARGARET KENNY
Director General
Chemical Sectors Directorate
On behalf of the Minister of the Environment

KAREN LLOYD
Director General
Safe Environments Directorate
On behalf of the Minister of Health

ANNEX

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

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 potential 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 upon application of the simple exposure and hazard tools developed by Health Canada for categorization of substances on the Domestic Substances List (DSL). Therefore, this assessment focuses on information relevant to the evaluation of ecological risks.

The substance was previously used in Canada as a dye and a printing ink based on use codes from the 1986 DSL. 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, the reporting threshold of 100 kg was used throughout this screening assessment to 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 would be released to sewer water (17.1%). 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, DADM would likely end up mostly in sediments. It is not expected to be significantly present in air.

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 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 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 representing industrial and consumer use releases to the aquatic environment were developed. 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 in water (PECs) were well below the predicted no-effect concentration (PNEC) calculated for sensitive aquatic species.

Based on the information available, DADM does not meet any of the criteria set out in section 64 of CEPA 1999.

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

Proposed conclusion

Based on the information available, DADM does not meet any of the criteria set out in section 64 of CEPA 1999.

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

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