Approaches to Chemical Prioritization for Risk Assessment

Transcription

1 Approaches to Chemical Prioritization for Risk Assessment Health Canada s Experience with Existing Substances under the Canadian Environmental Protection Act Heather Patterson Existing Substances Risk Assessment Bureau Safe Environments Directorate Healthy Environments and Consumer Safety Branch Health Canada

2 Introduction Context and Legislative framework Categorization of the Domestic Substances List (DSL) Chemicals Management Plan Multiple Approaches to Prioritization/Triaging of remaining Priorities High priorities Sector Approach Rapid Screening Substance Groupings Data Scoping Identification of Emerging Priorities Lessons Learned 11/6/2013 Page 2

3 Context and Legislative Framework The Canadian Environmental Protection Act (CEPA) First passed into law in 1988 CEPA was amended in 1999; new provisions were added Provides the regulatory framework and process for information collection, risk assessment and risk management of new and existing chemicals and organisms Has provisions for assessment of existing chemicals and organisms and requires every new substance made in Canada or imported from other countries to be assessed against specific criteria Requires the Minister of Environment to maintain an inventory of Existing Substances in Canada (Domestic Substances List). The DSL is the sole basis for determining whether a substance is new or existing in Canada 11/6/2013 Page 3

4 Categorization of the DSL Domestic Substances List (DSL) - list of substances that were in commerce in Canada between CEPA 1999 required Ministers of Environment and Health to categorize the ~23,000 substances on the DSL according to specific criteria to identify priorities for future assessment Categorization represented a priority setting exercise that involved the systematic identification of substances that should be subject to screening assessments and management controls if applicable Technical components of the methodology were subject to peer input and peer review and consultation was done with stakeholders and the public 4

5 CEPA Categorization of Existing Substances 23,000 Substances on CEPA s Domestic Substances List (DSL) These substances were in Canada between January 1984 and December 1986 Greatest Potential for Human Exposure Inherently Toxic to Humans Persistent or Bioaccumulative Inherently Toxic to Non-Humans Categorization criteria for potential harm 4,300 priority existing substances requiring assessment 5

6 Health Canada s Categorization of the DSL Simple tools were applied for both exposure and hazard to focus on identification of the highest priorities For the decision regarding which substances had the Greatest Potential for Exposure we focused on 3 lines of evidence based on initial data compiled for the DSL (1984 to 1986) : Quantity in commerce Number of submitters, and use codes For identifying hazard we focused on substances that have been classified by other agencies as CMRs When combined with priorities identified by Environment Canada 4300 substances were identified for future assessment work 11/6/2013 Page 6

7 Canada s Chemicals Management Plan The Chemicals Management Plan (CMP) is the Government of Canada s response to the Strategic Approach to International Chemicals Management (SAICM) designed to meet the 2020 goals set by the World Summit on Sustainable Development for sound management of chemicals The CMP provides a framework for assessment and management of the priorities identified through categorization The CMP integrates multiple federal programs into a single strategy to ensure that chemicals are managed appropriately in order to prevent harm to Canadians and their environment 11/6/2013 Page 7

8 Status of Assessments under the Chemicals Management Plan CMP was announced in 2006 First phase of the CMP Addressed the highest priority substances Initiated work on the low priority substances Second phase of the CMP Substance Groupings Initiative Third phase of the CMP Address the remainder of the priorities 8

9 First Phase of the CMP High priorities for action included substances (~500): That met each of the ecological categorization criteria (persistence (P), bioaccumulation (B) and inherent toxicity to aquatic organisms (it) ; and That met the criteria for greatest or intermediate potential for exposure (GPE or IPE) and were identified as posing a high hazard to human health (i.e., classified by another agency on the basis of carcinogenicity, mutagenicity, developmental toxicity or reproductive toxicity) The high priorities for action were addressed through 3 mechanisms: Significant New Activity (SNAcs) for substances believed to not be in commerce (~150 PBiT SNAcs) Challenge Program for substances believed to be in commerce (~ 200 substances) Petroleum Sector Stream a focused sectoral approach (~160 Substances) 11/6/2013 Page 9

10 Petroleum Sector Stream Approach Approximately 160 substances Manufactured or imported by the petroleum sector? yes no STREAM 0: Substances not manufactured or used by the petroleum sector no Leaving facility? yes Not in commerce In commerce but not petroleum substances (Coal Tars) (6 substances) STREAM 1: Site-restricted petroleum substances (68 substances) Industrial use only (e.g., feedstocks, fuels, lubricants, etc.) STREAM 2: Industry-restricted petroleum substances (16 substances) Final products used by the public or by other sectors STREAM 3: Fuels (13 substances) STREAM 4: Petroleum substances in consumer products (67 substances) 10

11 Health Canada s Rapid Screening Approach Example of exposure based prioritization (i.e., no exposure = no risk) Allows early identification of substances with low concern so that resources can be directed appropriately A number of substances identified through categorization have a low potential for risk due to low volumes in commerce in Canada Originally reported with low volumes or shifts in use patterns since 1980 s Three assessments on ~ 1200 have been completed using these approaches Assessments were published in April, May and June of 2013 Results indicate that ~700 of these substances need no further assessment The remaining 500 will be considered further in future assessments Further groups of substances will be triaged using this approach as data on current commercial status in Canada becomes available Rapid Screening of Substances Potential for Indirect Exposure NO YES Further Assessment Not 64 c NO Potential for Direct Exposure YES 11

12 Priority Considerations for the Second Phase of the CMP Potential Hazard and Exposure High hazard flags (internationally classified for health endpoints; high volume persistent, inherently toxic substances) Exposure potential as demonstrated through the recent industry survey and/or monitoring information Groupings to help find efficiencies and increase effectiveness Risk assessment (common chemical classes, modes of action, work already initiated in CMP, aggregate and cumulative exposure and risk) Risk management (common uses; common sector; industry stewardship/informed substitution) Scheduling Implications: Availability and timing of international information Ability of stakeholders to participate

13 Substance Groupings Initiative ~ 650 substances Aromatic azo and benzidine-based substances Substituted diphenylamines Cobalt-containing substances Methylenediphenyl diisocyanates and diamines (MDI/MDA) Selenium-containing substances Certain organic flame retardants Phthalates Boron-containing substances Certain Internationally Classified substances

14 Assessment Approaches for Categorization Priorities PBiT SNAcs: 145 Challenge Substances: 200 Substance Groupings Initiative: 500 Assessment Approach TBD: 1000 Polymer Approach: 700 Petroleum Sector Stream Approach: 164 Potential Future Petroleum Sector Stream: 200 Rapid Screening: 703 Future Rapid Screening:

15 Triage Considerations for the Third Phase of the CMP Grouping of substances Structure, Mode of action, Functional use, Possible substitutions Potential exposures Commercial status in Canada? How is it being used? Is it in consumer products? Has it been measured in environmental media or biomonitoring studies? Availability of toxicity data Is there empirical data? How much? Is it positive/negative? What endpoints are involved? Is there HTS data available? Scheduling opportunities Identification of possible opportunities for international collaboration Alignment with data generation 15

16 Indicator of Overall Data Availability Results of Toxline searching for all 2300 remaining priorities 14% 11% 4% 53% 0 hits 1-10 hits hits hits 100+ hits 18% 16

17 Identification of Emerging Priorities It is well recognized that scientific understanding of exposure and toxicity continues to evolve, and that global regulatory action on chemicals changes over time In an effort to effectively keep current, we monitor a variety of indicators (pertaining to exposure, hazard, or potential risk), and periodically analyse the information collected to evaluate whether or not further data gathering, assessment, or management activities should be undertaken in Canada Traditionally we use 7 feeders for identification of priorities Categorization Decisions Industry information Other jurisdiction decision International assessment or data collection Public nominations New Substance notifications Emerging science/monitoring Looking for ways to make this process more systematic and ensure that we are looking at all the appropriate pieces of information 17

18 Lessons learned to date Limitations to conducting a priority-setting exercise based on dated inventory data Lack of approaches to model substances other than organics (e.g., inorganics, UVCBs, etc.) Indirect exposures (i.e., environmental media) do not typically drive assessment outcomes though indoor air is a source of potential exposure Direct exposures (i.e., consumer products) more typically key driver in assessment outcome Scenarios typically are upper-bounding in nature with refinements if data is available Often data to refine was not easily obtained Exposure to substances that are present only as a residual/by-product can drive assessment outcomes (e.g., residual monomers) Substance-by-substance approach less efficient for both risk assessment and risk management activities Assessment of substance groupings can be challenging Groups built for one purpose are not always suitable for others (e.g., substances in groups built based on similar mode of action can have quite different uses/exposures) 11/6/2013 Page 18

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