Canada Gazette, Part I, Volume 147, Number 26: SUPPLEMENT
June 29, 2013
DEPARTMENT OF THE ENVIRONMENT
DEPARTMENT OF HEALTH
Publication of Final Decision after Screening Assessment of Substances — Batch 12
CAS No. 14464-46-1, CAS No. 14808-60-7
CAS No. 116-66-5, CAS No. 68583-58-4, CAS No. 101200-53-7
Publication of final decision after screening assessment of a substance — Guanidine, N,N′-diphenyl-, CAS RN (see footnote 1) 102-06-7 — specified on the Domestic Substances List (subsection 77(6) of the Canadian Environmental Protection Act, 1999)
Whereas Guanidine, N,N′-diphenyl- 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 Screening Assessment conducted on the substance pursuant to section 74 of the Act is annexed hereby;
And whereas it is concluded that the substance 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 the substance at this time under section 77 of the Act.
PETER KENT
Minister of the Environment
LEONA AGLUKKAQ
Minister of Health
ANNEX
Summary of the Screening Assessment Report of Guanidine, N,N′-diphenyl-
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 Guanidine, N,N′-diphenyl-, commonly referred to as diphenylguanidine or DPG, Chemical Abstracts Service Registry No. 102-06-7. DPG was identified as a high priority for screening assessment and included in the Challenge initiative under the Chemicals Management Plan because it was considered to pose an intermediate potential for exposure of individuals in Canada and had been classified by other agencies on the basis of reproductive toxicity. This substance met the ecological criteria for persistence, but not for bioaccumulation potential and inherent toxicity to aquatic organisms.
The substance DPG does not occur naturally in the environment. According to information received under section 71 of CEPA 1999, no companies reported manufacturing DPG in Canada in 2006, but 100 000–1 000 000 kg of DPG was imported into Canada and 100 000–1 000 000 kg of DPG was used. Less than 100 kg of DPG was reported to be released to air and, similarly, less than 100 kg of the substance was reported to be released to water in Canada in 2006. DPG is primarily used as an accelerator to achieve shorter curing times during the vulcanization process in the manufacture of rubber for tires and industrial applications. According to data submitted under section 71 of CEPA 1999, DPG is used in the manufacture of rubber tires, rubber mixtures, industrial rubber sheets, and sealants for automotive and navy applications in Canada.
Based on the available information, exposure of the general population in Canada to DPG through environmental media (except soil) is considered to be negligible. Exposure to DPG from dietary sources is not expected. According to the informa-tion available and industry data reported under section 71 of CEPA 1999, DPG is used in Canada to manufacture rubber material for tires and industrial applications. Exposure to DPG via soil containing tire debris was estimated and found to be low. Exposure of the general population from consumer products is not expected.
The critical health effect associated with exposure to DPG is reproductive toxicity, based on the observations in experimental animals and the weight-of-evidence classification by other international agencies.
The margin between upper-bounding estimates of exposure of the general population to DPG via contact with soil containing tire debris and the lowest effect level in experimental animals is considered adequate to address uncertainties in the health effects and exposure databases.
Based on the information available, it is concluded that DPG does not meet the criteria under paragraph 64(c) of CEPA 1999, as it 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 and modelled data, DPG meets the criteria for persistence, but not for bioaccumulation potential, as set out in the Persistence and Bioaccumulation Regulations. It is expected to have a moderate potential for toxicity to aquatic organisms, with highest potential for toxicity to certain species of algae. A risk quotient analysis, integrating conservative estimates of exposure with toxicity information, was performed for the aquatic medium to determine whether there is potential for ecological harm in Canada. The risk quotients indicated that the currently estimated site-specific industrial exposure concentrations of DPG in water are unlikely to cause harm to aquatic organisms. Based on this information, it is concluded that DPG does not meet the criteria in paragraphs 64(a) and (b) of CEPA 1999, as it 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.
Conclusion
Based on the information available, it is concluded that Guanidine, N,N′-diphenyl- does not meet any of the criteria set out in section 64 of CEPA 1999.
The 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 — Cristobalite, CAS RN 14464-46-1, and Quartz (SiO2), CAS RN 14808-60-7 — specified on the Domestic Substances List (subsection 77(6) of the Canadian Environmental Protection Act, 1999)
Whereas cristobalite and quartz are substances on the Domestic Substances List identified under subsection 73(1) of the Canadian Environmental Protection Act, 1999;
Whereas a summary of the Screening Assessment conducted on the substances pursuant to section 74 of the Act is annexed hereby;
And whereas it is concluded that the substances 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 the substances at this time under section 77 of the Act.
PETER KENT
Minister of the Environment
LEONA AGLUKKAQ
Minister of Health
ANNEX
Summary of the Screening Assessment Report of Cristobalite and Quartz
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 quartz, Chemical Abstracts Service Registry No. 14808-60-7 and cristobalite, Chemical Abstracts Service Registry No. 14464-46-1. These substances were identified as a high priority for screening assessment and included in the Challenge initiative under the Chemicals Management Plan. Quartz and cristobalite were identified as high priorities as they were considered to pose the “greatest potential for exposure” of individuals in Canada and their respirable forms are classified by the International Agency for Research on Cancer (IARC) as carcinogenic to humans (quartz and cristobalite) and by the U.S. National Toxicology Program as known human carcinogens (crystalline silica). These substances met the ecological categorization criteria for persistence, but not for bioaccumulation potential or inherent toxicity to aquatic organisms.
According to information reported under section 71 of CEPA 1999 for the year 2006, over 10 000 000 kg of quartz were manufactured, imported and used in Canada. Based on the results of the same survey, over 10 000 000 kg of cristobalite were manufactured and between 1 000 000 and 10 000 000 kg were imported and used in the year 2006.
It should be noted that these quantities do not represent the total quantities of quartz and cristobalite in the market in Canada because response to the mandatory section 71 notice was required only if the substance, product, mixture or manufactured item containing the substance was composed of more than 5% respirable crystalline silica and was intended for use within a residence. The major uses of quartz and cristobalite are in construction-related activities such as road building and sanding in winter, and as a cement additive. Other uses include the manufacture of glass fibres and ceramics, as a filler and extender in rubber and coatings, and as an abrasive.
Quartz and cristobalite are both naturally occurring. Quartz is found abundantly in many types of rock formations, while cristobalite can be found in the ashes of volcanic eruptions. Cristobalite is less prevalent than quartz as its presence is limited to specific geographic regions and rock types.
Quartz and cristobalite were qualitatively found to be very persistent because they are extremely resistant to chemical weathering. Also, quartz and cristobalite were qualitatively found to not bioaccumulate in aquatic organisms since they are expected to have very limited potential for uptake through for example the gills or gut of fish. Respirable fractions may physically accumulate in the lung tissues of terrestrial organisms. Results from available experimental toxicity studies indicate that quartz and cristobalite are not highly hazardous to aquatic organisms. In mammals, however, the crystalline phases can cause harm to the lung (e.g. silicosis) depending on the severity and duration of exposure.
Quartz and cristobalite meet the criteria for persistence, but do not meet the criteria for bioaccumulation, as set out in the Persistence and Bioaccumulation Regulations. A risk quotient analysis at eight Canadian sites, integrating conservative to very conservative estimates of exposure via inhalation with a predicted no-effect concentration, resulted in risk quotients below one, indicating that the exposure concentrations of quartz and cristobalite in air that are currently estimated are unlikely to cause harm to terrestrial fauna. On the basis of this evidence, it is concluded that these substances do not meet the criteria in paragraphs 64(a) and (b) of CEPA 1999, as they are 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.
Concentrations of silicon in respirable particulate matter in Canada were identified and used to estimate inhalation exposure to quartz and cristobalite for the general population. The major anthropogenic releases of airborne respirable quartz and cristobalite are expected to come from dust generated due to agriculture, construction activity, and vehicle traffic on unpaved and paved roads.
The International Agency for Research on Cancer (IARC) has classified respirable quartz and cristobalite from occupational exposure as Group 1 carcinogens (carcinogenic to humans). The U.S. National Toxicology Program classified crystalline silica of respirable size as known to be a human carcinogen. The basis for these classifications is sufficient evidence from human studies indicating a causal relationship between exposure to respirable crystalline silica in the workplace and increased lung cancer rates in workers. While the mode of induction of lung tumours is not fully elucidated, sufficient data exists to demonstrate that a threshold approach to risk characterization is appropriate.
On the basis of the adequacy of the margins between conservative estimates of the exposure to quartz and cristobalite from ambient air and critical effect levels in experimental animals and humans, it is concluded that quartz and cristobalite do not meet the criteria in paragraph 64(c) of CEPA 1999, as they are 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.
Conclusion
Based on the information available, it is concluded that quartz and cristobalite do not meet any of the criteria set out in section 64 of CEPA 1999.
The 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 substance — Silanamine, 1,1,1-trimethyl-N-(trimethylsilyl)-, reaction products with ammonia, octamethylcyclotetrasiloxane and silica, CAS RN 68937-51-9 — specified on the Domestic Substances List (subsection 77(6) of the Canadian Environmental Protection Act, 1999)
Whereas Silanamine, 1,1,1-trimethyl-N-(trimethylsilyl)-, reaction products with ammonia, octamethylcyclotetrasiloxane and silica 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 Screening Assessment conducted on the substance pursuant to section 74 of the Act is annexed hereby;
And whereas it is concluded that the substance 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 the substance at this time under section 77 of the Act.
PETER KENT
Minister of the Environment
LEONA AGLUKKAQ
Minister of Health
ANNEX
Summary of the Screening Assessment Report of Silanamine, 1,1,1-trimethyl-N-(trimethylsilyl)-, reaction products with ammonia, octamethylcyclotetrasiloxane and silica
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 Silanamine, 1,1,1-trimethyl-N-(trimethylsilyl)-, reaction products with ammonia, octamethylcyclotetrasiloxane and silica, Chemical Abstracts Service Registry No. 68937-51-9. This substance will be referred to by its derived acronym, OMSSA, in the screening assessment. This substance was identified as a high priority for screening assessment and included in the Challenge initiative under the Chemicals Management Plan because it was found to meet the ecological categorization criteria for persistence, bioaccumulation potential and inherent toxicity to non-human organisms and is believed to be in commerce in Canada.
The substance OMSSA 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.
The substance OMSSA belongs to a class of chemicals described as Unknown or Variable Composition, Complex Reaction Products, or Biological Materials (UVCBs). This substance consists of the reaction products of 1,1,1-Trimethyl-N-(trimethylsilyl)-silanamine (HMDS) [CAS RN 999-97-3], Octamethylcyclotetrasiloxane (D4) [CAS RN 556-67-2] and Synthetic amorphous silica (SAS) [CAS RN 7631-86-9]. In the present assessment, this substance is represented by its major component (>90%), a surface-treated Synthetic amorphous silica (SAS) component. It is noted that D4 is a reaction residual in OMSSA, present at up to 5% of the final composition of this substance. D4, as a discrete substance, has been assessed in 2008 under the Challenge initiative, and it was concluded that the substance posed an ecological risk.
The substance OMSSA is used in Canada and elsewhere in industrial settings as a component in the production of silicone sealant and silicone rubber. No manufacture of OMSSA was reported in response to section 71 survey notices for the 2005 or 2006 calendar years. However, OMSSA imports to Canada were greater than 100 000 kg in 2005 and just under 100 000 kg in 2006.
Based on its physical and chemical properties and the expected lack of biodegradation of the SAS component of OMSSA, it is expected that OMSSA is persistent in air, water, soil and sediments. Based on the available information regarding uptake of the treated SAS, the representative component of OMSSA, through various routes of exposure, OMSSA does not appear to be bioaccumulative in organisms. Therefore, the substance meets the persistence criteria but does not meet the bioaccumulation criteria as set out in the Persistence and Bioaccumulation Regulations.
There were no ecotoxicological data identified for OMSSA. Based on the experimental data, both surface-treated SAS and untreated SAS present low toxicity to aquatic organisms.
Available information regarding the ecological risk associated with the currently estimated exposure concentrations of OMSSA in water suggests that OMSSA is unlikely to cause ecological harm in Canada. Therefore, considering the available information, it is concluded that OMSSA does not meet the criteria in paragraphs 64(a) and (b) of CEPA 1999, as it 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.
On the basis of the health effects information for an analogue of OMSSA, Silane, dichlorodimethyl-, reaction products with silica (CAS RN 68611-44-9), the possible health effects associated with exposure to OMSSA are mainly on the respiratory system. However, the potential for exposure of the general population to OMSSA from environmental media is expected to be negligible. Exposure to OMSSA from consumer products is not expected because it is only used in industrial settings. Since the exposure of the general population to OMSSA is expected to be low, the risk to human health is expected to be low. It is, therefore, concluded that OMSSA does not meet the criteria in paragraph 64(c) of CEPA 1999, as it 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.
Conclusion
Based on the information available, it is concluded that Silanamine, 1,1,1-trimethyl-N-(trimethylsilyl)-, reaction products with ammonia, octamethylcyclotetrasiloxane and silica does not meet any of the criteria set out in section 64 of CEPA 1999.
The 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 — Carbon black, CAS RN 1333-86-4 — specified on the Domestic Substances List (subsection 77(6) of the Canadian Environmental Protection Act, 1999)
Whereas carbon black 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 Screening Assessment conducted on the substance pursuant to section 74 of the Act is annexed hereby;
And whereas it is concluded that the substance 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 the substance at this time under section 77 of the Act.
PETER KENT
Minister of the Environment
LEONA AGLUKKAQ
Minister of Health
ANNEX
Summary of the Screening Assessment Report of Carbon Black
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 carbon black, Chemical Abstracts Service Registry No. 1333-86-4. Carbon black was identified as a high priority for screening assessment and included in the Challenge initiative under the Chemicals Management Plan because it was considered to pose the “greatest potential for exposure” of individuals in Canada and had been classified by other agencies on the basis of carcinogenicity. This substance met the ecological categorization criteria for persistence, but not the criteria for bioaccumulation potential and inherent toxicity to aquatic organisms.
Carbon black is not naturally produced in the environment; it is manufactured by the controlled vapour-phase pyrolysis and partial combustion of gaseous or liquid hydrocarbons. In 2006, according to information reported under section 71 of CEPA 1999, 227 900 000 kg of carbon black were manufactured in Canada and 26 400 000 kg were imported. Carbon black is used primarily in the rubber industry as a reinforcing filler and as a pigment in a variety of products including inks, paints and coatings, and plastics. In Canada, carbon black can also be present in a limited number of food products, cosmetics, pharmaceuticals and natural health products, pesticides, and in food packaging. According to information reported under section 71 of CEPA 1999, 10 000–100 000 kg of carbon black were reported to be released to land, 10 000–100 000 kg to air, and 1 000–10 000 kg to water in 2006.
The human health risk characterization focuses on scenarios in which the general population can be exposed to carbon black by inhalation, given the limited potential for exposure and uptake via the oral and dermal routes and the lack of reported acute or chronic toxicity via these routes. No empirical data were identified on the concentrations of carbon black in the environment. Accordingly, exposure from environmental media in the vicinity of a carbon black manufacturing facility was characterized using dispersion modelling. With respect to consumer products, carbon black is used in a large number of paints and coatings, some with potential for inhalation exposure and exposure estimates were derived for these scenarios. Carbon black is also an ingredient in certain costume spray hair dyes and an exposure estimate was derived for this scenario.
Based principally on the weight-of-evidence assessments of international agencies, a critical effect for characterization of risk to human health for carbon black is carcinogenicity. Increased incidences of lung tumours were observed in female rats exposed by inhalation to the only or lowest concentration tested in one 11-month and two 2-year bioassays. However, the weight of evidence indicates that the induction of lung tumours in rats following carbon black exposure is caused by an excessive lung burden (i.e. particle overload) due to overwhelming and impairment of clearance mechanisms, resulting in an oxidative state. No evidence was available to indicate carcinogenicity by the oral or dermal routes of exposure. Genotoxicity data indicate that carbon black has the potential to cause DNA and chromosome damage. However, these effects are probably mediated by indirect mechanisms involving inflammation resulting from particle overload in the lung, resulting in the generation of reactive oxygen species, oxidative stress, and oxidative DNA damage. As the tumours observed in animals are considered unlikely to have resulted from direct interaction with genetic material, a margin of exposure approach is used to characterize risk to human health.
The critical effect level for acute pulmonary non-cancer effects by inhalation is a lowest observed effect concentration (LOEC) of 1 mg/m3 in male rats exposed to carbon black for seven hours, based on a significantly higher prevalence of inflammation and oxidative stress compared with controls. The critical effect level for chronic pulmonary non-cancer effects by inhalation is a LOEC of 0.57 mg/m3, based on increased respiratory symptoms and decreased lung function measurements in individuals (male) exposed to carbon black in an occupational setting.
The margins between upper-bounding estimates of airborne exposure to carbon black in the environment or from consumer products and levels associated with respiratory effects are considered to be adequate to address uncertainties in the health effects and exposure databases. On the basis of the adequacy of the margins between conservative estimates of exposure to carbon black and critical effect levels in animals, it is concluded that carbon black does not meet the criteria in paragraph 64(c) of CEPA 1999, as it is not entering the environment in a quantity or concentration or under conditions that constitute or may constitute a danger to human life or health in Canada.
Carbon black is not soluble, and when released into water it is expected to eventually settle into sediments. Carbon black is resistant to hydrolysis, photolysis and biodegradation; it is therefore persistent in the environment. Accumulation in the tissues of living organisms is not an ecological concern, as carbon black’s physical and chemical properties do not make bioaccumulation possible. It is expected to have very low potential for toxicity to aquatic organisms. Although no environmental monitoring data were identified, conservative exposure concentrations were estimated in surface water near industrial sources. Conservative risk quotient analysis, comparing predicted environmental concentrations with a predicted no-effect concentration, resulted in risk quotients of less than one, indicating that carbon black is unlikely to cause harm to aquatic organisms.
Based on the information available, it is concluded that carbon black does not meet the criteria in paragraphs 64(a) and (b) of CEPA 1999, as it 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. Carbon black has been determined to meet the persistence criteria but not the bioaccumulation potential criteria, as set out in the Persistence and Bioaccumulation Regulations.
Conclusion
Based on the information available, it is concluded that carbon black does not meet any of the criteria set out in section 64 of CEPA 1999.
The 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 — Pyridine, alkyl derivs., CAS RN 68391-11-7 — specified on the Domestic Substances List (subsection 77(6) of the Canadian Environmental Protection Act, 1999)
Whereas the substance pyridine, alkyl derivs. is on the Domestic Substances List identified under subsection 73(1) of the Canadian Environmental Protection Act, 1999;
Whereas a summary of the Screening Assessment conducted on the substance pursuant to section 74 of the Act is annexed hereby;
And whereas it is concluded that the substance 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 the substance at this time under section 77 of the Act.
PETER KENT
Minister of the Environment
LEONA AGLUKKAQ
Minister of Health
ANNEX
Summary of the Screening Assessment Report of Pyridine, alkyl derivs.
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 pyridine, alkyl derivs., Chemical Abstracts Service Registry No. 6839111-7. This substance was identified in the categorization of the Domestic Substances List as a high priority for action under the Challenge. Pyridine, alkyl derivs. was identified as a high priority as it was considered to pose the “greatest potential for exposure” of individuals in Canada and is classified by other agencies on the basis of carcinogenicity. The substance met the ecological categorization criteria for persistence but did not meet the criteria for bioaccumulation potential or inherent toxicity to aquatic organisms.
According to information submitted under section 71 of CEPA 1999, pyridine, alkyl derivs. was not reported to be manufactured by any company in Canada during the calendar year of 2006 above the 100 kg reporting threshold. However, 1 000 000– 10 000 000 kg of the substance were reported to be imported in 2006. The major use of pyridine, alkyl derivs. is corrosion inhibition of oil and gas wells and pipelines in Canada and this use is considered the principal source of potential releases to the environment through cleaning/washing of tanker trucks and periodic pipeline leaks under normal operating conditions. More minor uses of pyridine, alkyl derivs. include as a formulant in one registered herbicide, a corrosion inhibitor in industrial cleaning and de-scaling products for closed water heat transfer systems, and an incidental additive in cleaning products for food contact surfaces.
As defined by the Chemical Abstracts Service, pyridine, alkyl derivs. is the complex combination of polyalkylated pyridines derived from coal-tar distillation or as high-boiling distillates approximately above 150°C from the reaction of ammonia with acetaldehyde, formaldehyde or paraformaldehyde. This is also the Domestic Substances List (DSL) definition. Therefore, this assessment only directly considers the polyalkylated components of the complex mixture. However, commercial versions of the substance in Canada may contain production by-products, such as non-alkylated pyridines, which are considered to be outside of the DSL definition.
Exposure of the general population to pyridine, alkyl derivs. through environmental media was estimated based upon the principal use in Canada, i.e. corrosion inhibition in the oil and gas extraction industry, which accounts for over 90% of the total use quantity in 2006. Conservatively estimated annual release quantities from process and occasional leaks are considered to be very low. While pyridine, alkyl derivs. is present in some cleaning products for food contact surfaces, dietary exposure for the general population from this source is not expected, as a potable water rinse is required after cleaner application. In addition, while various alkyl pyridines were identified in a variety of foods and beverages, pyridine, alkyl derivs. as a complex mixture as defined by the Chemical Abstracts Service would not be expected in foods or beverages and, therefore, dietary exposure is not expected.
Based on the limited empirical health effects information available, it is considered that the major components of pyridine, alkyl derivs. within the Chemical Abstracts Service definition, i.e. discrete short chain alkylated pyridines, such as mono-, di-, tri-methylpyridines, ethylpyridines, methylethylpyridines and propylpyridines, are not highly hazardous. It is likely that the hazard potential of pyridine, alkyl derivs. is due to the presence of by-products in commercial versions of the substance, such as non-alkylated derivatives of pyridine.
As exposure of the general population through environmental media in Canada is expected to be negligible, and exposure is not expected from foods or beverages or consumer products, the risk to human health is considered to be low.
Based on the information available, it is concluded that pyridine, alkyl derivs. does not meet the criteria in paragraph 64(c) of CEPA 1999, as it 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 mostly on empirical biodegradation data, the substance is not expected to degrade quickly in the environment. It is persistent in air, water, soil and sediments. This substance does not have the potential to accumulate in organisms or to biomagnify in trophic food chains. The substance has been determined to meet the persistence but not the bioaccumulation criteria as set out in the Persistence and Bioaccumulation Regulations. Empirical aquatic toxicity values indicate that the substance is not highly hazardous to aquatic organisms.
For this screening assessment, a realistic worst-case exposure scenario was selected in which an industrial operation discharges pyridine, alkyl derivs. into the aquatic environment. The conservative predicted environmental concentration in water (PEC) was less than the very conservative predicted no-effect concentration (PNEC) calculated based on effects data for green algae.
Based on the information available, it is concluded that pyridine, alkyl derivs. does not meet the criteria in paragraphs 64(a) and (b) of CEPA 1999, as it 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.
Conclusion
Based on the information available, it is concluded that pyridine, alkyl derivs. does not meet any of the criteria set out in section 64 of CEPA 1999.
The 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 three substances — 1H-Indene, 2,3-dihydro-1,1,3,3,5-pentamethyl-4,6-dinitro-, CAS RN 116-66-5; Ethanamine, N-ethyl-N-hydroxy-, reaction products with hexamethylcyclotrisiloxane, silica and 1,1,1-trimethyl-N-(trimethylsilyl)silanamine, CAS RN 68583-58-4; and Pyridine, 2-[3-(3-chlorophenyl)propyl]-, CAS RN 101200-53-7 — specified on the Domestic Substances List (subsection 77(6) of the Canadian Environmental Protection Act, 1999)
Whereas 1H-indene, 2,3-dihydro-1,1,3,3,5-pentamethyl-4,6-dinitro-; ethanamine, N-ethyl-N-hydroxy-, reaction products with hexamethylcyclotrisiloxane, silica and 1,1,1-trimethyl-N-(trimethylsilyl)silanamine; and pyridine, 2-[3-(3-chlorophenyl) propyl]- are substances on the Domestic Substances List identified under subsection 73(1) of the Canadian Environmental Protection Act, 1999;
Whereas a summary of the Screening Assessment conducted on the substances pursuant to section 74 of the Act is annexed hereby;
Whereas it is concluded that the substances 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 these substances,
Notice therefore is hereby given that the Ministers of the Environment and of Health propose to take no further action on these substances at this time under section 77 of the Act.
PETER KENT
Minister of the Environment
LEONA AGLUKKAQ
Minister of Health
ANNEX
| CAS RN (see footnote 2) | Domestic Substances List name |
|---|---|
| 116-66-5 | 1H-indene, 2,3-dihydro-1,1,3,3,5-pentamethyl-4,6-dinitro- |
| 68583-58-4 | ethanamine, N-ethyl-N-hydroxy-, reaction products with hexamethylcyclotrisiloxane, silica and 1,1,1-trimethyl-N-(trimethylsilyl)silanamine |
| 101200-53-7 | pyridine, 2-[3-(3-chlorophenyl)propyl]- |
The above-mentioned three substances on the Domestic Substances List (DSL) were identified as high priority for screening assessment, to be part of the Challenge under the Chemicals Management Plan, because they meet 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. However, 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. Also, they are not on the European Union’s Candidate List of Substances of Very High Concern for Authorisation.
Pursuant to paragraph 74(a) of CEPA 1999, the Ministers of the Environment and of Health have conducted a screening assessment of these substances.
Results from notices issued under paragraph 71(1)(b) of CEPA 1999 on March 4, 2006, and December 26, 2009, as part of the Challenge revealed no reports of industrial activity (import or manufacture) with respect to these substances in Canada, above the reporting threshold of 100 kg, for the specified reporting years of 2005 and 2006, respectively. These results indicate that in 2005 and 2006, these substances were not in use above the specified reporting threshold; therefore, the likelihood of exposure to this substance in Canada resulting from commercial activity is low. Other sources of entry into the environment have not been identified at this time.
Responses to the above-mentioned notices issued under paragraph 71(1)(b) of CEPA 1999 and the accompanying questionnaire of December 26, 2009, also revealed no new information relevant to the PBiT properties of these substances. Given the lack of any significant commercial activity for these substances, no further collection or analysis relevant to the persistence, bioaccumulation and ecological effects of these substances, beyond what was done for categorization, has been completed for the substances bearing CAS No. 68583-58-4 and CAS No. 101200-53-7. However, new information on ecotoxicity and environmental fate for musk moskene, CAS No. 116-66-5, has been considered since categorization. The results of an experimental study on biodegradation in water indicate that the substance bearing CAS No. 116-66-5 is not inherently biodegradable; therefore, it is also not readily biodegradable. This result is in agreement with the estimates from three models indicating that the substance (CAS No. 116-66-5) is not readily biodegradable. Low experimental water solubility and high experimental log Kow values suggest that the substance (CAS No. 116-66-5) is a lipophilic substance which is expected to be bioaccumulative in aquatic organisms. When experimental water solubility and log Kow values are used as inputs in bioconcentration/bioaccumulation models, the modelled data indicate that the bioconcentration potential of this substance is very high. Two additional ecotoxicological studies for the substance (CAS No. 116-66-5) have been identified. The results from these studies were considered as inconclusive and contradictory. The study by Schramm et al. (1996) contains an inconclusive result [no effects at saturation, i.e. a median effects concentration (EC50)>0.046 mg/L]. In the other study (Chou and Dietrich, 1999), a statistically significant reduction of the viability of frog larvae (62% to 94%) was observed. New experimental and modelled data confirm that this substance is highly persistent and bioaccumulative as defined in the Persistence and Bioaccumulation Regulations of CEPA 1999, and has inherent toxicity.
As mentioned above, given the lack of evidence that these substances are in use in Canada or abroad, and since the results from notices issued under paragraph 71(1)(b) of CEPA 1999 on March 4, 2006, and December 26, 2009, indicate that these substances are not in use above the specified reporting threshold, the likelihood of exposure to the general population in Canada is considered to be low; hence, the potential risk to human health is considered to be low. Furthermore, 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. Also, they are not on the European Union’s Candidate List of Substances of Very High Concern for Authorisation.
Conclusion
Based on available information, and until new information is received indicating that these substances are entering or may enter the environment from commercial activity or from other sources, it is concluded that the above-mentioned substances are currently 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 constitute a danger to the environment on which life depends or that constitute a danger in Canada to human life or health. Therefore, it is concluded that they do not meet any of the criteria as set out in section 64 of CEPA 1999.
As they are listed on the DSL, import and manufacture of these substances in Canada are not currently subject to declaration under subsection 81(1). Given the hazardous PBiT properties of the substances, as well as the potential hazard to human health associated with the substance bearing CAS RN 116-66-5, there is concern that new activities for the substances which have not been identified or assessed under CEPA 1999 could lead to the substances meeting the criteria as 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 the substances are 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 declared and will undergo ecological and human health risk assessments as specified in section 83 of the Act, prior to the substances being considered for introduction into Canada.
The Screening Assessment for these substances is available on the Government of Canada’s Chemical Substances Web site (www.chemicalsubstances.gc.ca).