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Substances Identified for Screening Health Assessment

HC Screening State of the Science Reports Update to the ICG February 14th/05 Presented by: Bette Meek Existing Substances Division Health Canada. Priority Substances Assessment. Small. More. Focussed Screening Assessment (Phase III). Assessment Complexity & Extent of Documentation.

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Substances Identified for Screening Health Assessment

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  1. HC Screening State of the Science Reports Update to the ICGFebruary 14th/05Presented by: Bette MeekExisting Substances DivisionHealth Canada

  2. Priority Substances Assessment Small More Focussed Screening Assessment (Phase III) Assessment Complexity & Extent of Documentation Issue Identification for Health Priorities (Phase II) Number of Substances Tools-Based Priority Setting and Assessment of Non-Health Priorities (Phase I) Less Substances Identified for Screening Health Assessment Large No. of Substances Categorization of the Domestic Substances List (DSL) Review of Decisions of Other Jurisdictions Public Nominations

  3. Principle/Nature of the Documentation Models No more assessment and/or documentation than is necessary to identify non-priorities; robust advice/process for priorities with efficiencies gained in early issue identification Tools based screening assessments or exposure-based reports for non-priorities: • Defensibility relates principally to the robustness of the “tools” and completeness of the search strategies • Concise, tabular documentation of output, with more complete supporting information available on request (e.g., pesticide, only)

  4. Principle/Nature of the Documentation Models (Cont’d) Full, focussed screening assessments for high priorities: • Brief State of the Science report focussing on critical information (9 about to be released) • Currently, supporting document with limited text content and considerable tabular presentation, which documents how critical data were identified • In future, for health assessments, supporting documents will be principally tabular output - use and hazard profiles, Issue Identifications and any documentation prepared to address critical issues

  5. Health State of the Science Reports • Present the technical/scientific basis for screening assessments • Post external peer review & management approval of process/content • No proposed/final Ministerial conclusions • Released via ExSD ListServe & posted on EXSD website to: • provide early indication of basis for impending conclusions • encourage timely, voluntary action, where appropriate

  6. Health State of the Science Reports(Cont’d) • Associated conclusions and/or measures proposed in accordance with relevant Sections and paragraphs of CEPA 1999 will be released for comment in the Canada Gazette • Public comment period initiated when Gazette Notice issued • State of the Science report may or may not be revised on basis of public comment • Often public comment addresses issues other than science

  7. Health State of the Science Reports - Advantages • Timeliness of release & currency of reviewed information • Increased transparency • Clear separation of science base from other considerations • Ensures clear delineation of non-science based considerations • Increased efficiency to meet common goals • Release independent of complex regulatory process • Less requirement to continually revise • Early opportunity for voluntary “fit for purpose” action

  8. State of the Science for Full Focussed Assessments Biphenyl (92-52-4) MBMBP (119-47-1) DNOC (534-52-1) MBOCA (101-14-4) 1,2-Dibromoethane (106-93-4) Hexachloroethane (67-72-1) 1,1-Dichloroethylene (75-35-4) Ethyl benzene (100-41-4) Quinoline (91-22-5) Not Priorities for Assessment at this Time 6 pesticides in the pilot phase based principally on use profiling Portion of the 42 Section 71 Non-Reports based principally on use profiling Releases (or Upcoming) from the Pilot Phase

  9. Implications of DSL for Content of State of the Science/Assessment Reports • For health, we have “binned” all substances on the DSL in the context of its priority, both by group and within group • E.g., GPE, HH • IPE, HH • LPE, HH (n = 3 of the 9 substances) • Within each of the groups, we can additionally sort by increasingly refined estimates of exposure and hazard • This information is also relevant in screening

  10. What is Output of SoS/Assessment Report? • Binning on the basis of priority (as per entire DSL) • Estimate of risk (comparison of exposure and effect) • Delineation of uncertainties/critical information gaps • Trends in production/use • Identification of principal media (& where possible), sources of exposure • “Right sized” risk management or next steps • Notice

  11. What’s Different than PSL? • Considering much larger numbers of substances permitting integration across compounds • Less emphasis on scientific/technical data on individual compounds without context of considerations across substances • Much more integrated approach in order to “right size” recommended risk management • Welcoming “right sized” voluntary initiatives from stakeholders • Implication for risk management strategies • HC initiatives more targetted to human exposure • E.g., indoor air strategy

  12. Example 1 of Considerations from an SoS Report for Next Steps (i.e., Gazette Notice) • Release to the environment through industrial waste streams, glycol dehydrators, fuel combustion and emissions from consumer products • Very high volume; use increasing (GPE/HH on maximal list) • Indoor air is the primary medium of human exposure • Products likely important since levels indoors > outdoors • Carcinogenic without weight of evidence for a non-DNA reactive mdoe of action • Moderate to high confidence in exposure • Moderate to high confidence in effects

  13. Example 1 of Considerations from an SoS Report for Next Steps (i.e., Gazette Notice) • Risk based “priority for investigation of risk management measures” is high in comparison to other health “toxics” in screening assessments Possible Next Steps • Critical mode of action data for cancer? • What steps are being taken to control releases? • Target as part of indoor air quality initiative

  14. Example 2 of Considerations from an SoS Report for Next Steps (i.e., Gazette Notice) • Used in industrial settings as heat transfer fluid • Use decreasing – IPE/HH on maximal list • Also dispersed into environment through vehicle exhaust, emissions from residential and industrial heating devices and cigarette smoke • Indoor air and possibly food are major media of human exposure • Combustion sources • Carcinogenic without weight of evidence for a non-DNA reactive mode of action • High confidence that estimated exposures are conservative • Moderate to high confidence in health effects database

  15. Example 2 of Considerations from an SoS Report for Next Steps (i.e., Gazette Notice) (Cont’d) • Risk based “priority for investigation of risk management measures” is low to moderate in comparison to other health “toxics” in screening assessments • Potential to reduce exposure from dispersive combustion? • Target combustion sources as part of indoor air quality strategy

  16. Implications of DSL for Testing Strategies • For individual substances, the need for intelligent testing strategies integrating both potential exposure & predictive hazard tools • E.g., volume” inadequate in designating priorities • Value of use profiling • Implications for “minimum datasets” • Screening Initial Datasets • The need for an integrated approach for testing across substances • The importance of considering uncharacterized chemical space in testing versus individual substances • In some cases, risk management may be preferable to generation of critical data for individual substances

  17. The Communications Challenge • Increasing understanding of the more integrative approach across substances

  18. More Information? • Health Canada Existing Substances Division Website – http://www.hc-sc.gc.ca/ewh-semt/contaminants/existsub/index_e.html • Health Canada Maximal List and Integrated Proposal Framework – http://www.hc-sc.gc.ca/ewh-semt/contaminants/existsub/framework-cadre_e.html • Health Canada Existing Substances Mailing List – http://www.hc-sc.gc.ca/ewh-semt/contaminants/existsub/mail-avis_e.html • CEPA Registry – http://www.ec.gc.ca/CEPARegistry/default.cfm

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