Rapid Screening of Substances identified from Phase Two of the Domestic Substances List Inventory Update

Results of the Screening Assessment

Environment and Climate Change Canada
Health Canada

August 2016

(PDF Format - 1 025 KB)

Table of contents

• Synopsis
• Introduction
• Approach
  • Ecological component
  • Human health component
• Screening Assessment Results
  • Assessment of potential to cause ecological harm
  • Assessment of potential to cause harm to human health
• Summary of uncertainties
• Conclusion
• References
• Appendicies
  • Appendix A: Number of substances for which data was available, by source
  • Appendix B: Substances identified as requiring further assessment
  • Appendix C: Substances identified as not meeting the criteria under section 64 of CEPA 1999
  • Appendix D: Masked substances identified as not meeting the criteria under section 64 of CEPA 1999
  • Appendix E: Substances identified as having ecological effects of potential concern
  • Appendix F: Substances identifed as having classifications for health effects of concern by other national or international agencies

Synopsis

As part of the Government of Canada 's Chemicals Management Plan, a section 71 notice for the second phase of the Domestic Substances List (DSL) Inventory Update (IU) initiative was published in the Canada Gazette, Part I on December 1, 2012 to collect data on approximately 2700 substances. As a result, 869 substances were identified as candidates for rapid screening. The substances included in this report were candidates for rapid screening because they were identified as being in commerce across Canada at a total of less than or equal to 1000 kg/year, according to information submitted pursuant to section 71 of Canadian Environmental Protection Act, 1999 (CEPA) regarding commercial activity in Canada under Phase Two of the DSL IU.

The majority of the 869 substances met the categorization criteria for persistence or bioaccumulation and inherent toxicity to human or non-human organisms or for greatest potential for exposure to humans under subsection 73(1) of CEPA. Some substances considered in this assessment had been identified as having health effects of concern based on classifications by other national or international agencies for carcinogenicity, genotoxicity, developmental toxicity or reproductive toxicity.

A rapid screening approach was applied that involved using conservative assumptions to identify substances that warrant further evaluation of their potential to cause harm to either human health or the environment, and those that are expected to have a low likelihood of causing harmful ecological or human health effects.

The ecological component consisted of two main steps to identify substances that warrant further evaluation of their potential to cause harm. The first step involved applying different exposure scenarios using assumptions that are protective of the environment. The second step involved a mechanical process to identify whether or not a substance appears on any of a wide range of lists or in sources of information relating to ecological hazard or exposure. This step recognized substances that have been identified by domestic or international initiatives as possibly being of greater concern due to their ecological hazard properties, or elevated potential for environmental release.

The human health component consisted of a process to determine whether the substance warrants further assessment based on the potential for exposure to the general population. Substances reported to be in commerce in Canada at less than or equal to 1000 kg/year are considered to warrant further assessment only if there is evidence of direct exposure (e.g., exposure from products or processed foods) for the general population in Canada. If the potential for exposure is considered to be negligible for a substance, then it is concluded that that substance is unlikely to cause harm to human health at current levels of exposure.

In total, 257 substances were identified as requiring further assessment (40 identified for both ecological and human health considerations, 199 identified for human health considerations only, and 18 identified for ecological considerations only). For the remaining 612 substances, this rapid screening approach indicated that current use patterns and quantities in commerce are unlikely to result in concerns for organisms or the broader integrity of the environment, or for human health in Canada. Although a risk to the environment or human health has not been identified for 612 substances, 39 of these substances in this assessment are recognized to have properties or effects of concern. There may be a concern for the environment or for human health if exposures to these substances were to increase.

Considering all available lines of evidence presented in this screening assessment, there is low risk of harm to organisms and the broader integrity of the environment from the 612 substances identified in Appendix C and D. It is concluded that the 612 substances do not meet the criteria under paragraphs 64(a) or 64(b) of CEPA 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.

From a human health perspective, direct or indirect exposure to the general population from environmental media (air, water, soil) to these 612 substances is expected to be negligible, and therefore the substances are unlikely to cause harm to human health at current levels of exposure. Based on the information presented in this screening assessment, it is concluded that the 612 substances listed in Appendix C and D do not meet the criteria under paragraph 64(c) of CEPA 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

It is concluded that these 612 substances do not meet any of the criteria set out in section 64 of CEPA.

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Introduction

The Canadian Environmental Protection Act, 1999 (CEPA) (Canada 1999) requires the Minister of the Environment and the Minister of Health to conduct screening assessments of substances that have met the categorization criteria set out in subsection 73(1) of the Act to determine whether these substances present or may present a risk to the environment or human health^Footnote1.

Under CEPA, screening assessments focus on information critical to determining whether a substance meets the criteria for defining a chemical as toxic as set out in section 64 of the Act, where:

"64. [...] a substance is toxic if it is entering or may enter the environment in a quantity or concentration or under conditions that

1. have or may have an immediate or long-term harmful effect on the environment or its biological diversity;
2. constitute or may constitute a danger to the environment on which life depends; or
3. constitute or may constitute a danger in Canada to human life or health."

The Government of Canada has identified 869 substances as candidates for a rapid screening approach. Thirty-two substances from the Confidential Domestic Substances List (CDSL) were included as a part of the 869 substances in this rapid screening. A confidential Accession Number is given to a substance whose identity has been identified as confidential pursuant to paragraphs 3 to 7 of the Masked Name Regulations. Their identities have been masked according to sections 88 and 113 of CEPA in this report.

The 869 substances were identified as being in commerce at a total quantity across Canada of less than or equal to 1000 kg/year as reported through submission of information provided in response to a notice under section 71 of CEPA 1999 regarding commercial activity in Canada under Phase Two of the Domestic Substances List (DSL) Inventory Update (Canada 2014). The majority of these substances met the categorization criteria for persistence or bioaccumulation and inherent toxicity (PiT or BiT) to human or non-human organisms for Greatest Potential for Exposure (GPE), or under subsection 73(1) of CEPA. Substances may have additionally been identified as having health effects of concern based on classifications by other national or international agencies for carcinogenicity, genotoxicity, developmental toxicity or reproductive toxicity.

Substances that meet the above quantity criteria, but that have already been assessed and managed under CEPA, or are currently being addressed under other assessment activities, are not included in this assessment. Furthermore, assessments and conclusions pertaining to some of the substances in this rapid screening may be subsequently updated as part of future assessments if the substance is found to be part of a larger class or moiety. This assessment incorporates input from other programs within Environment Canada and Health Canada. Additionally, the draft of this Screening Assessment was subject to a 60-day public comment period. While external comments were taken into consideration, the final content and outcome of the screening assessment remain the responsibility of Health Canada and Environment Canada.

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Approach

Ecological component

The ecological component of the rapid screening approach, as illustrated in Figure 1, consists of multiple steps that address different factors relating to the potential for a substance to cause ecological harm. The approach is intended to be pragmatic, protective of the environment, and fairly rapid, largely making use of available or easily obtainable data and evaluation of the data.

Step 1: Modelled exposure scenarios

The first step in the ecological component involves applying different scenarios or fate models to estimate environmental exposure. Two generic aquatic exposure scenarios were applied (described hereafter as scenarios A and B) to identify potential concerns near the point of discharge of a substance to the environment. These involve comparing conservative (i.e., ecologically protective) estimates of exposure in receiving waters with an effects threshold to evaluate whether a chemical is expected to cause harm to the local aquatic environment. A regional multi-media model named RAIDAR (Risk Assessment, IDentification And Ranking) is also applied. This fugacity-based model (described hereafter as scenario C) takes into account the combined characteristics of the substance in estimating potential harm in different environmental media (water, soil, and air), as well as in food chains. Figure 2 illustrates these exposure estimation approaches.

These approaches make use of available data from DSL categorization activities and Phase Two of the DSL Inventory Update. Data from the DSL Inventory Update includes use and quantity information from each reporting company. For those substances for which no data was received or the quantity reported was less than 100 kg, 100 kg was used for the quantity in the environmental exposure models. Data collected or estimated during categorization (Canada 2013) includes pivotal values for acute aquatic toxicity (iT), persistence and bioaccumulation, as well as physical/chemical properties.

While the generic aquatic exposure scenarios (A and B) have been developed to be conservative overall, the level of conservatism applied to individual parameters was selected to be moderate, since it is recognized that:

• a high level of conservatism applied to each parameter can easily compound into an excessively conservative overall exposure scenario;
• it is very unlikely that each parameter would be "worst case" at the same time; and
• interdependency of some parameters exists.

Rather, values in keeping with an overall worst case scenario have been used.

Scenario A: Industrial point source aquatic release

Scenario A is based on release from an industrial facility that is manufacturing the substance and/or using it in the blending or preparation of products. This scenario assumes the release of 5% of the substance from manufacturing and blending activities, based on conservative estimates for loss from cleaning of container residues (3%), transfer lines (1%) and process equipment (1%) (US EPA 1992). A conservative estimate of exposure (predicted environmental concentration (PEC)) resulting from the release of the substance to the aquatic environment from such an industrial point source is calculated as shown in the following equation.  Parameters used in Exposure Scenario A are described in Table 1.

PEC (mg/L) = (Qty (kg) x Release (%) x (1 – Wastewater Removal (%)))/(Duration (days) x (River flow (m³/s) + Wastewater flow (m³/s))) x (1000 (L/m³)/86400 (s/day))

The aquatic predicted no-effect concentration (PNEC) is derived as shown

Aquatic PNEC (mg/L) = CTV (mg/L)/AF

The PEC is compared to the PNEC to determine a risk quotient (PEC / PNEC). If the risk quotient is greater than one, this indicates that the conservatively estimated concentration in water exceeds the aquatic estimated no-effect level and that there exists a potential to cause harm in the aquatic ecosystem. A quotient below one indicates that concentrations that may cause an effect to sensitive aquatic organisms are not reached and therefore harm to aquatic organisms is unlikely under this scenario.

Scenario B: Down-the-drain aquatic release from consumer products

The second scenario (residential releases to wastewater) considers the down-the-drain release of 100% of the substance that is contained in a consumer product, from multiple point-sources (i.e., wastewater system). While not all substances inherently have the characteristics that lend themselves to down-the-drain applications, this scenario is used to represent a worst-case. Under this scenario, a value for the PEC from down-the-drain release of a substance contained in products is calculated, as well as a value for the aquatic PNEC, as defined in the equations below. Parameters used in exposure scenario B are described in Table 2 below.

PEC (mg/L) = (Qty (kg) x Release (%) x (1 – Wastewater Removal (%)) x Population (persons))/(Duration (days) x RPE (persons)(River Flow (m³/s) + Wastewater Flow (m³/s) ))) x (1000 (L/m³)/86400 (s/day))

PNEC(mg/L) = CTV (mg/L)/AF

As was the case for Scenario A, the PEC and the PNEC are combined to determine a risk quotient (PEC / PNEC).

Note that river flow distributions used in the two scenarios are different. Likelihood of harm from industrial releases (scenario A) is dependent on the number of industrial facilities releasing to a water body. In that scenario, a distribution of the dilution capacities of receiving waters (river flow) was generated with a weighting by the number of industrial facilities releasing to the water body. Likelihood of harm from down-the-drain release of consumer products (scenario B) is dependent on the human population that may be releasing a substance to a wastewater treatment system. In this scenario, a distribution of the ratio of population of the community to the dilution capacity of the receiving water body was generated. As a result, the parameters "population", "wastewater flow rate" and "river flow" are inter-connected. In this scenario, it is this ratio that is important, not the actual values of the population or flow rates.

Scenario C: Life cycle release

Scenario C uses a fugacity-based multimedia modelling approach to address possible release of the substance over its full life-cycle. Such models assume substances released to the environment are distributed throughout a unit world – and are thus suitable for a disperse release scenario from all stages of the substance life-cycle (Mackay 2001).

This modelling approach also provides a "safety net" scenario, since it accounts for combined effects of a substance 's physical/chemical and hazard properties as well as considerations of exposure to different environmental media (water, air, soil, sediment) and organisms.

RAIDAR is a peer-reviewed fugacity-based model developed by the Canadian Environmental Modeling Network (CEMN) to assess chemicals for risk by estimating environmental fate and transport, bioaccumulation and exposure to organisms, and determining a critical emission rate (Arnot et al. 2006; Arnot and Mackay, 2008). An updated RAIDAR Ver.2.0 was used to run the simulations. The model has been revised to better address the fate and bioaccumulation for ionogenic organic chemicals (Armitage et al. 2013, Arnott 2011a,b)

A Level III fugacity model scenario was used to model the partitioning of substances into the environment. In this model, the substance is assumed to be continuously discharged at a constant rate and achieves a steady state condition in which input and output rates are equal. The loss processes are degradation reactions and advection. Unlike the simpler Level II fugacity model, equilibrium between media is not assumed and, in general, each medium is at a different fugacity. The Level III fugacity model scenario was run assuming a 33% release of the substance to each of air, water and soil for interpretation of RAIDAR results in this rapid screening approach. For ionogenic organic chemicals the scenario was run assuming a 100% release of the substance to water, since the substance is expected to partition to water.

Representative food webs are included in RAIDAR to assess routes of exposure of organisms to chemicals in the environment. The food web model takes the output from the fate and transport calculations for the substance (the concentration in the different environmental media) and estimates internal concentrations in some 20 biotic groups including plankton, vegetation, domestic animals, fish and wildlife, using data on the nature and quantity of diets, respiration, and growth rates. Essentially, each organism absorbs the chemical by respiring air (or by exchange at the gill-water interface in the case of fish) or by consuming water and other organisms (plants or animals). The concentration of the substance in each organism is generally calculated using these rates, absorption efficiencies, and the concentration in the respective media. The steady-state concentration in the organism is calculated from an input-output mass balance. The result is an estimate of fugacity and concentrations in the biota.

Using a multi-level, multi-media foodchain, the most sensitive endpoint is identified (based on toxicity and exposure potential) and a "critical emission rate" is calculated based on that sensitive endpoint. The estimated critical emission rate is then compared with an estimated potential emission rate (based on quantities in commerce) to determine a "risk assessment factor" or RAF.

Substances are ranked according to their critical emission rates and their RAF values. Substances identified as having greater potential for harm are considered as requiring further assessment. The model output also indicates substances that are unlikely to be of concern from releases to the environment through their life-cycle.

As outlined in a report on the application of RAIDAR in rapid screening (Arnot and Mackay 2007), there are some classes of substances (e.g., inorganic substances) for which application of the model was not designed or may not be appropriate. Substances belonging to such classes were identified and the model was not applied to them. A more detailed description of RAIDAR is contained in Environment Canada (2007a).

For the purpose of the rapid screening approach, the critical emission rate, the RAF and the media of concern are the most important outputs of RAIDAR. The use of the critical emission rate and the RAF allows identification of chemicals that are unlikely to be of concern because of their limited potential for exposure. Additionally, the identification of the most sensitive ecological endpoint allows consideration of environmental media and/or types of organisms that may not have been previously addressed in the rapid screening exposure scenarios A and B.

Possible outcomes from Step 1

There are three possible outcomes from Step 1:

• If the scenarios indicate a potential harmful effect to aquatic or terrestrial organisms and the substance is reported to be in commerce, based on information collected under the DSL Inventory Update, the substance is identified as requiring further assessment;
• If the scenarios indicate a potential harmful effect to aquatic or terrestrial organisms and the substance is believed not to be in commerce (i.e., no response received or stakeholder interest only), based on information collected under the DSL Inventory Update, the substance is considered as having low likelihood of harm, but may be monitored for changes in the use profiles; or
• If the scenarios indicate a low likelihood of harm to organisms, then the substance proceeds to the next step of rapid screening.

Decisions regarding the need for future monitoring of changes in the use profiles are made when a new activity in relation to a substance could result in the substance being released in amounts or under conditions that may result in the substance posing an environmental risk. In the ecological portion of this screening assessment, decisions to recommend monitoring of changes in use profiles may be triggered for substances which are not currently in commerce (based on information collected under the DSL Inventory Update), but which could have a risk quotient value above one, if as little as 100 kg of the substance was brought into commerce. Based on back-calculation using the conservative ecological rapid screening exposure scenarios A (Industrial Point Source Aquatic Release) or B (Down-the-Drain Aquatic Release from Consumer Products), such a situation could occur if a substance has an acute aquatic toxicity value (lethal concentration to 50% of study organism (LC₅₀) or equivalent) less than or equal to 0.0061 mg/L.

Step 2: Mechanical filters and manual processes

The second step of the ecological rapid screening approach involves verifying various information sources to confirm the likelihood that a substance may be of ecological concern. This approach uses "filters" (i.e., various information sources) and involves identifying whether or not a substance appears on different lists or sources of information relating to hazard or exposure. This step identifies substances that may have an elevated potential for environmental release or that have been identified by domestic or international sources as possibly being of greater concern due to their hazard properties.

Depending on the nature of the information sources, substances identified by the filters may be further evaluated manually within rapid screening or be identified as requiring further assessment. This manual process involves case-by-case evaluation to decide, for example, whether the information in the source that identified the substance is relevant to the situation in Canada. It may also involve collection and review of information from other sources that are not as amenable to evaluation using a mechanical approach. The manual process involves evaluation of the weight and relevance of information obtained from the full range of sources identified.

Many sources of information were evaluated. In selecting which lists or information sources to apply in rapid screening, there was an effort to limit the amount of overlap between lists. For example, secondary sources of information were removed if the primary source of information was also included. A list of the sources of information that were retained for the purpose of rapid screening can be found in Appendix A. A number of information sources were judged to be relevant for rapid screening, but were not amenable to being searched mechanically. These sources were included among those verified at the manual stage.

Possible outcomes from Step 2

There are two possible outcomes from Step 2:

• If the mechanical filters and/or manual process indicate a potential harmful effect to the environment, the substance is identified as requiring further assessment; or
• If the mechanical filters and manual process indicate a low likelihood of harm to the environment, then the substance is unlikely to cause ecological harm.

Human health component

The process used to determine whether substances warrant further assessment from a human health perspective within the rapid screening approach is illustrated in Figure 3.

A key element of the characterization of potential risk to human health is determination of potential for exposure to the general population. Substances reported to be in commerce in Canada at less than or equal to 1000 kg/year were considered to result in potential exposure to the general population if there was evidence of direct exposure (e.g., exposure from products or processed foods). Otherwise, exposure to the general population was considered to be negligible and it can be concluded that the substance is unlikely to cause harm to health at current levels of exposure.

Given the reported quantities in commerce in Canada (less than or equal to 1000 kg) of these substances, indirect exposure to the general population from environmental media (e.g. air, water, soil) is not expected to be significant. Release of a substance to specific environmental media (i.e., water, air, soil) depends on factors such as where the substance is released and its physical/chemical properties. Conservative modelling estimates using a fugacity based modelling tool for applicable substances (ChemCan 2003), indicate that assuming 100% release of a substance (i.e., the maximum possible release for these substances of 1000 kg) to either air, water or soil, potential exposures would be predicted to be less than 10-6 mg/kg bw/day (i.e., less than 1 ng/kg bw/day). This represents a negligible exposure potential from indirect sources for these substances.

Depending on the use of the substance, direct exposure to the general population may be possible. Considerations for determination of direct exposure potential are described below and outlined in Figure 4.

The term "direct use" refers to the use of a chemical substance that is directly, or as part of a mixture, a product, or a manufactured item, sold to or made available to Canadians for their use.

"Direct use" does not include exposures from chemical products used by workers in an industrial setting or other workplace.

A user is considered to be anyone from the general public who has access to a product that is advertised, imported or sold in Canada^Footnote2.

To determine if a substance is used in or present in a product used by Canadians, numerous sources of both domestic and international use and product information were consulted, including but not limited to:

Domestic

• Information from a mandatory CEPA 1999 section 71 survey under - Phase Two of the DSL Inventory Update (Canada 2012);
• Health Canada 's Lists of permitted food additives (2013);
• Health Canada 's Natural Health Products Ingredients Database (NHPID 2014);
• Health Canada 's Licensed Natural Health Products Database (LNHPD 2014);
• Health Canada 's Drug Product Database (DPD 2014);
• Pest Management Regulatory Agency Product Information Database (PMRA 2014);
• Pest Management Regulatory Agency List of Formulants (PMRA 2010);
• List of Pharmaceuticals sold in Canada (2011 & 2012) (IMS 2013); and
• Notifications submitted under the Cosmetic Regulations to Health Canada.
• Notifications submitted under the Food and Drugs Act to Health Canada

International

• US EPA Chemical and Product Categories Database (CPCat 2014);
• Everything Added to Food in the United States Database (EAFUS 2011);
• US Food and Drug Administration 's Food Additive Status List (US FDA 2013);
• US Food and Drug Administration 's List of Indirect Additives used in Food Contact Substances (US FDA 2011);
• European Commission 's Food Additive database (EU 2014a);
• European Commission 's Food Flavourings database (EU 2014b);
• European Commission 's Cosmetic Ingredient database (COSING 2014);
• Household Products Database (HPD 2014);
• Hazardous Substances Data Bank (HSDB c1993-2008);
• Danish Surveys on Chemicals in Consumer Products- Various (Denmark 2014);
• Material Safety Data Sheets (MSDS)- various internet sources; and
• National and international assessments and databases;

Based on the information identified from these resources, the following considerations were used to determine potential for direct exposure:

1. Substances to which direct exposures to the general population are not expected include, but are not limited to, substances:
   1. used only as intermediates in the manufacturing process;
   2. used only for industrial use; or
   3. used only for research purposes.
2. Substances with potential for direct exposure to the general population include those that are present, either intentionally or unintentionally, in products or manufactured items that are commonly used by Canadians. These include, but are not limited to, substances used in:
   • products intended for use by children, and manufactured items such as plastic or wooden toys;
   • personal care products^Footnote3;
   • commercial paints and inks;
   • commercial adhesives;
   • hobby activities or do-it-yourself products;
   • clothing, fabric and other textiles, including bedding and furniture
   • cleaning products;
   • food additives and packaging; or
   • fragrances or flavourants^Footnote4.
3. Information on potential for the substance to migrate from products was also considered, including the type of product that the substance is present in, the substance 's functional use in that product, as well as the substance 's physical-chemical properties. For example, direct exposure would not be expected to occur for a substance used as a curing agent in a polymer as the substance would be reacted into the stable matrices of the cured polymer and would therefore not typically be available for migration. If this information is not known for a substance, it was assumed that the substance may be migrating out of the final product, which may lead to direct exposure for users.

Through the evaluation, some uses were identified that could result in direct exposure; however, these uses are already being regulated under other Acts:

1. Fertilizers- The direct use of fertilizers is regulated under the Fertilizers Act. As a consequence, if the only use (with a potential for direct exposure) identified for a substance was as a fertilizer (or component thereof), that use was considered to be regulated under the Fertilizers Act^Footnote5, and as a result, this use was no longer considered in the evaluation. These substances have been flagged in Appendix C;
2. Pharmaceuticals – The direct use of pharmaceuticals is regulated under the Food and Drugs Act. This use was not considered further in the evaluation of potential for direct exposure to the general population in this screening assessment. Substances which were found to be used only in pharmaceutical (veterinary and/or human) applications, with information indicating volume levels less than 1000 kg per year in Canada, have been identified as requiring no further action in this rapid screening approach. These substances have been flagged in Appendix C;
3. Pesticide formulants –In situations where the only use identified for a substance was as a formulant in a pesticide product registered under the Pest Control Products Act(PCPA), this potential for direct exposure to the general public was not considered further in this screening assessment. Substances in pest control products registered under the PCPA have undergone an ecological and human health risk assessment by the Pest Management Regulatory Agency (PMRA) according to the intended use and labelling as part of their registration process. The substances used as formulants were considered separately from those identified as active ingredients in registered pesticide products, as the formulants, while components of pesticide products, do not provide a function(s) that is/are unique to pesticides. However, in the case of the formulants flagged in Appendix C, no uses were identified in Canada for these substances, other than their listing as pesticide formulants (PMRA 2010); and
4. Historical active pesticide ingredients- these are substances which were registered as active ingredients in pesticide products in Canada historically, but do not have any current registered uses in pesticides in Canada. These substances have been flagged in Appendix C.

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Screening Assessment Results

Assessment of potential to cause ecological harm

In this section, an overview of the results obtained at each step of rapid screening of the substances covered under this assessment is provided. These results are summarized in Figure 5.

Step 1: Modelled exposure scenarios

In this assessment, quantities that were used in the exposure scenarios were obtained through the Phase Two of the DSL Inventory Update (Canada 2012).

Generic aquatic scenarios

The industrial releases scenario (scenario A) identified 129 substances as being of potential concern, while the residential releases scenario (scenario B) identified 86 substances, all of which were also identified by the industrial release scenario. These 129 substances (or 15% of the 869 evaluated) were initially identified by these scenarios as requiring further assessment. However, results from the Second Phase of the DSL Inventory Update indicate that 77 of these 126 substances are no longer in commerce in Canada above the reporting threshold (i.e. 100 kg). As indicated in the ecological component portion of the Approach section of this report, activities with as low as 100 kg per year of a substance could pose a risk if that substance has an acute aquatic toxicity value (LC₅₀ or equivalent) less than or equal to 0.0061 mg/L. 

Of the above-mentioned 77 substances, 46 substances are not expected to be a significant contributor to the presence of the substance in the environment. For example, there are a number of  substances where the pivotal inherent toxicity value identified during categorization of the DSL and applied in this rapid screening evaluation, was based on the ecotoxicity of the free metal ion expected to be liberated during dissolution/transformation of the substance under natural conditions. For example, an organic metal salt will dissolve and liberate a metal cation and an anionic organic moiety when present in water. However, in the case of these substances--all of which are believed to have very little or no commercial presence at this time--becoming a significant contributor to the presence of the total metal moiety in the environment in the future, relative to other sources of release, is unlikely. Therefore, only 31 of these substances are proposed flagged as having ecological effects of potential concern (see Appendix E).

RAIDAR

RAIDAR and similar models are not applicable to all categories of substances encountered on the DSL. RAIDAR was applied to substances described in Arnot and Mackay (2007): conventional organics; dissociating organic acids; and dissociating organic bases. Therefore, of the 869 substances evaluated in Step 1, 236 (or 27%) were modelled using RAIDAR. However, higher confidence was only achieved with the modelling of the organic substances. A spreadsheet includes all input values and results from application of RAIDAR to these substances (ARC 2014). As with other models, results from RAIDAR depend on the quality and quantity of the available substance-specific data.

In order to identify which substances are unlikely to have the potential to cause ecological harm, it is necessary to select a cut-off value for the RAF. A value of 0.001 was selected, which is equivalent to an uncertainty factor of 1000. Selection of this conservative value allows for up to a 1000-fold error in the model results owing to uncertainties in the quantity of the substance in commerce and other model inputs, such as physical-chemical properties. The ability of RAIDAR to discriminate potential for ecological harm based on the characteristics of substances is discussed further in Environment Canada (2007b).

Based on the described model scenario and the selected RAF cut-off value, 23 of the 236 substances that were evaluated using RAIDAR were identified as having potential for harmful effects if released at the reporting thresholds used in the DSL Inventory Update  (Figure 6) and thus requiring further assessment. RAIDAR identified three additional substances for further assessment beyond the substances identified in release scenarios A and B.

Step 2: Mechanical filters and manual process

Appendix A shows the number of substances that were identified by each of the mechanical filters for the 869 substances that were evaluated in this rapid screening exercise. In contrast to the rapid screening approach outlined in Environment Canada 2007a, the appearance of a substance on one or more of the six international lists of High Production Volume (HPV) chemicals did not automatically result in the substance being identified for further assessment due to the availability of recent Canadian data (Canada 2014) on these substances. Substance-by-substance evaluation at the manual process stage was based on consideration of the available information to evaluate whether the substance has hazard properties or characteristics, or an elevated potential for environmental release, that may not have been adequately addressed using the exposure scenarios in Step 1.

As a result of manual screening, six substances were identified as requiring further screening assessment due to additional toxicity data.

Summary of results from ecological assessment

In total, 58 of the substances evaluated using the ecological rapid screening approach were identified as warranting further assessment from an ecological perspective. A list of these substances is provided in Appendix B. The other 811 substances were identified as posing a low risk of harm to organisms or the broader integrity of the environment at current levels of exposure. Thirty-one of these substances were identified as having potential ecological effects of concern as a result of their relatively high aquatic toxicity (Appendix E).

Assessment of potential to cause harm to human health

Of the 869 substances examined from a human health perspective, 239 substances were identified as having the potential to result in direct exposure to the general population and therefore warrant further assessment of the exposure and hazard potential of these substances. A list of the substances with potential for direct exposure to the general population, and therefore requiring further assessment, is provided in Appendix B.

Exposure to the general population was considered to be negligible for the remaining 630 substances

However, eight substances not identified for further assessment at this time may be recommended to be monitored for changes in use profiles (identified in Appendix C) based on high hazard concerns. These substances have been identified as havinghealth effects of concern based on classifications by other national or international agencies for carcinogenicity, genotoxicity, developmental toxicity or reproductive toxicity (see Appendix F).

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Summary of uncertainties

It is recognized that conclusions resulting from the use of a rapid screening approach have associated uncertainties. However, the use of a wide range of filters (relating to both exposure potential and hazard concerns identified for each substance), as well as the use of conservative exposure scenarios give confidence that substances identified as not requiring further assessment are unlikely to be of concern.

Values for physical/chemical and hazard properties derived during categorization of the DSL were used as input for the modelling work for the ecological assessment. As is recognized in documentation associated with categorization, there are uncertainties in these values, in particular with those that have been estimated using different modelling approaches. Extreme values that were estimated by models were replaced by limiting values of physical/chemical properties or alternatively-derived toxicity values, prior to using them as input for RAIDAR modelling as part of rapid screening (ARC 2014).

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Conclusion

In total, from both ecological and human health assessments, 257 of the 869 substances were identified as requiring further assessment (Appendix B).

Based on the information available, it is concluded that the remaining 612 substances 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, that constitute or may constitute a danger to the environment on which life depends, or that constitute or may constitute a danger in Canada to human life or health. It is therefore concluded that these 612 substances (Appendix C and D) do not meet any of the criteria set out in section 64 of CEPA 1999.

As these 612 substances are listed on the DSL, they are not subject to notification under the New Substance Notification Regulations (Chemicals and Polymers). Although a risk to the environment or human health has not been identified, 39 substances (31 ecological, 8 human health) in this assessment are recognized to have properties or effects of concern (see Appendix E and F). There may be a concern for the environment or for human health if exposures to these substances were to increase. 

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References

ARC. 2014. Parameterization and Application of the RAIDAR Model to Support Prioritization and Assessment of Substances. Report prepared by ARC Arnot Research & Consulting Inc., Toronto, ON, for the Existing Substances Division, Environment Canada, Gatineau, QC, Canada.

Armitage, J. M., J.A. Arnot, F. Wania, D. Mackay 2013. Development and evaluation of a mechanistic bioconcentration model for ionogenic organic chemicals in fish. Environ. Toxicol. Chem. 32: 115-128, Arnot, J.A., D. Mackay, E. Webster and J. Southwood. 2006. Screening level risk assessment model for chemical fate and effects in the environment. Environ. Sci. Technol. 40:2316-2323

Arnot, J. and Mackay, D. 2007. Risk prioritization for a subset of Domestic Substances List chemicals using the RAIDAR model. Report prepared by the Canadian Environmental Modelling Centre, Trent University, ON, for the Existing Substances Division, Environment Canada, Gatineau, QC, Canada. CEMC Report No.: 200703.

Arnot, J. A., D. Mackay 2008. Policies for chemical hazard and risk priority setting: Can persistence, bioaccumulation, toxicity and quantity information be combined? Environ. Sci. Technol. 42: 4648-4654.

Arnot, J. A. 2011a. Updating the raidar and fhx models to aid in the prioritization and assessments of chemicals including ionisable substances. Draft technical report for Health Canada.; Health Canada: Ottawa, ON, March 25, 2011; p 39.

Arnot, J. A. 2011b. Exploring the fate, bioaccumulation and exposure potential of ionogenic chemicals released to the environment using the raidar model. Draft technical report prepared for unilever.; ARC Arnot Research & Consulting Inc.

Canada. 1999. Canadian Environmental Protection Act, 1999. S.C., 1999, c. 33.

Canada. 2012. Canadian Environmental Protection Act, 1999: Notice with respect to certain inanimate substances (chemicals) on the Domestic Substances List, Vol. 146, No. 48, 1 December, 2012.

Canada. 2013. Search engine for the results of DSL Categorization. [March 2014].

Canada. 2014. Draft results from Phase Two of the Domestic Substances List Inventory Update. Environment Canada, Gatineau, QC, Canada

ChemCAN [Level III fugacity model of regional fate of chemicals]. 2003. Version 6.00. Peterborough (ON): Trent University, Canadian Centre for Environmental Modelling and Chemistry.

COSING. 2014. European Cosmetic ingredient inventory [database on the internet]. European Commission Cosmetics Directive. [March 2014].

[CPCat] Chemical and Product Categories [database on the inventory]. 2014..U.S. Environmental Protection Agency. [May 2014].

Denmark. 2014. Danish Surveys on Chemicals in Consumer Products. Danish Ministry of the Environment (Danish EPA). Copenhagen, Denmark. [March 2014].

[DPD] Drug Products Database [database on the Internet]. 2014. Ottawa (ON): Therapeutic Products Directorate, Health Canada. [February 2014].

[EAFUS] Everything Added to Food in the United States [Internet]. 2013. U.S. Food and Drug Administration; [cited 2014 February].

EC. 2014a. European Commission Food Additives Database [database on the internet]. European Commission Directorate General Health & Consumers. Brussels, Belgium. Taken from Annex II of Regulation (EC) No 1333/2008. (cited 2014 March).

EC. 2014b. European Commission Food Flavourants database [database on the internet]. European Commission Directorate General Health & Consumers. Brussels, Belgium. Taken from Part I of Annex I of Regulation (EC) No 1334/2008. (cited 2014 March).

Environment Canada. 2007a. Technical Approach for "Rapid Screening" of Substances of Lower Ecological Concern. Existing Substances Division, Environment Canada, Gatineau, QC, Canada.

Environment Canada. 2007b. Results of the Rapid Screening Assessment of Substances of Lower Ecological Concern – Supplementary Evaluation of RAIDAR Modelling Results. Existing Substances Division, Environment Canada, Gatineau, QC, Canada.

Environment Canada. 2014. Results from Phase Two of the Domestic Substances List Inventory Update Rapid Screening Assessment of Substances of Lower Ecological Concern – Detailed Spreadsheet. Ecological Assessment Division, Environment Canada, Gatineau, QC, Canada.

EPA 1986] United States Environmental Protection Agency. 1987. United States Environmental Protection Agency (US EPA) The Risk Assessment Guidelines of 1986. EPA/600/8-87/045, Sep 1987. Office of Health and Environmental Assessment. Washington, D.C.

[ESIS] European Chemical Substances Information System [database on the Internet]. ©1995–2010. European Commission, Joint Research Centre. [cited 2012 Jan 18].

Health Canada. 2013. Lists of Permitted Food Additives.

[HPD]. Household Products Database [database on the internet]. 2014. U.S. Department of Health & Human Services; [cited 2014 January]. Available from:

[HSDB] Hazardous Substances Data Bank [database on the internet]. c1993-2008. United States National Library of Medicine, National Institutes of Health; [cited 2013 December]. Available at: http://toxnet.nlm.nih.gov/cgi-bin/sis/htmlgen?HSDB

[IARC] International Agency for Research on Cancer Working Group on the Evaluation of Carcinogenic Risks to Humans. 1996. Printing Processes and Printing Inks, Carbon Black and Some Nitro Compounds. IARC Monogr Eval Carcinog Risks Hum 65.

[IMS] IMS. 2013. Health Canada Sales Database 2011 & 2012 [ MIDAS database on CD]. IMS Brogan,Toronto (ON), IMS Brogan  

[LNHPD] Licensed Natural Health Products Database [database on the internet]. 2014. Health Canada, Government of Canada; [Accessed January-February 2014].

Mackay, D. 2001. "Multimedia Environmental Models: The Fugacity Approach - Second Edition", Lewis Publishers, Boca Raton, pp.1-261.

[NHPID] Natural Health Products Ingredients Database [database on the internet]. 2014. Health Canada, Government of Canada; [Accessed January-February 2014].

[NTP]. National Toxicology Program 13^th Report On Carcinogens (ROC). United States Department of Health and Environmental Service.

[PMRA]. Pest Management Regulatory Agency Product Information Search [database on the internet]. 2014. Health Canada, Government of Canada; [cited 2014 January].

[PMRA]. Pest Management Regulatory Agency. 2010. List of Formulants. HC Pub #: 100460. Health Canada, Government of Canada; [verified with PMRA January 2014].

U.S. EPA. 1992.Chemical Engineering Branch. Memorandum: Standard Assumptions for PMN Assessments. From the CEB Quality Panel to CEB (Environment Canada) Staff and Management. October 1992.

U.S. EPA. 2005. Guidelines for Carcinogen Risk Assessment. EPA/630/P-03/001F. March 2005.

US FDA 2011. List of Indirect Additives Used in Food Contact Substances [database on the internet]. U.S. Food and Drug Administration. [data last updated 14 November 2011].

US FDA. 2013. Food Additive Status List. [Retrieved February 2014] US Food and Drug Adminstration [data last updated 21 March 2013].

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Appendicies

Appendix A: Number of substances for which data was available, by source

Appendix B: Substances identified as requiring further assessment

^aChemical Abstracts Service Registry Number

Appendix C: Substances identified as not meeting the criteria under section 64 of the Canadian Environmental Protection Act, 1999 (CEPA 1999)

^a This substance was not identified under subsection 73(1) of CEPA but was included in this assessment as it was considered as priorities based on other human health concerns.

^*Additional details on use type flagged are provided in the Human Health Component.

Appendix D: Masked substances identified as not meeting the criteria under section 64 of CEPA 1999

 

Appendix E: Substances proposed not to meet Section 64 of CEPA 1999 but that were identified as having hazard classifications by other national or international agencies

^a Chemical Abstracts Service Registry Number.

* Substances with iT values from Categorization below 0.0061 mg/L.

Appendix F: Substances identified as not meeting the criteria under Section 64 of CEPA 1999 but that were identified as having classifications for health effects of concern by other national or international agencies

^a Chemical Abstracts Service Registry Number