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Chemical Safety Assessment and Reporting Tool (Chesar), REACH
Chemical Safety Assessment and Reporting Tool (Chesar), REACH MJ Ramos-Peralonso, Green Planet Environmental Consulting, Madrid, Spain Ó 2014 Elsevier Inc. All rights reserved.
Introduction The CHEmical Safety Assessment and Reporting tool (Chesar) is an application developed by the European Chemicals Agency (ECHA) to help companies carry out their chemical safety assessments (CSAs) under the European REACH Regulation and to prepare their chemical safety reports (CSRs) that must be included in the REACH registration dossiers and the exposure scenarios (ES) that also should be added to the extended safety data sheets (SDSs) for communication in the supply chain. The CSR is a regulatory requisite that must be included in the registration dossiers for chemicals registered under the REACH Regulation and manufactured or imported above 10 tons per year. Basically, Chesar has implemented as an IT tool the principles related to the CSA as described in the ECHA “Guidance on Information Requirements and Chemical Safety Assessment.” Chesar is directly connected to IUCLID, the electronic database system for storing and presenting the information on the substance identity, its uses, and the hazard information (physical–chemical properties, ecotoxicology, and toxicology end-points). Chesar has been developed as a ‘plugin’ for IUCLID5. Chesar provides a structured workflow for carrying out a standard safety assessment for the different uses of a substance, but provides enough flexibility to accommodate specific situations. The tool also helps to structure the information needed for the exposure assessment and risk characterization, facilitating the generation of a transparent CSR. Chesar allows both quantitative and qualitative risk assessments. The quantitative assessments are based on predicted no-effect levels for human health and for the environment. Under REACH, the predicted no-effect levels for human health assessment are named DNELs, Derived No-Effect Levels, and those for environmental protection, PNECs, Predicted NoEffect Concentrations. Regarding the quantitative exposure assessment, Chesar has combined three complementary generic exposure assessment models, the ECETOC TRA models for workers and for consumers and the EUSES 2.1 fate model for predicting the environmental concentrations. Chesar can also be used in assessments based on other exposure estimation tools or measured data; however, no automated calculation of exposure estimates can be performed in these cases, and the exposure data should be introduced manually. Qualitative risk characterization approaches are used when hazards are identified for a substance but the information does not permit setting predicted no-effect levels. In these cases Chesar supports ES building with qualitative risk characterization. The main aim of Chesar is to increase the efficiency when conducting CSAs under REACH and to provide consistency between CSAs and the information communicated to downstream users, with the automated generation of CSRs and ESs. Chesar facilitates the reuse (or update) of assessment elements generated in Chesar or imported from external
Encyclopedia of Toxicology, Volume 1
sources, and has considered developments by industry, such as generic exposure scenarios (GESs) or specific environmental release categories (SpERCs). It also enables the use of the phrase catalog and the information exchange format for ESs that have been developed under Cefic’s ESCom project.
Chesar Workflows Chesar is divided into seven major groups of functionalities called Boxes. All Boxes are connected and contribute to the generation of the CSR and/or the ES for the extended SDS: l
Box 1: Manage substance. It is used for importing the hazard information from the IUCLIC dossier. This includes the conclusions from the hazard assessment, directly determining the scope of exposure assessment and the type of required risk characterization (qualitative or quantitative). Chesar is used once the hazard assessment according to Annex I of REACH has been finalized, and consequently all the information related to those substances’ intrinsic properties (single end-point summaries and overall toxicological and ecotoxicological summaries) needed for the exposure assessment and risk characterization is available in IUCLID. This information is imported into Chesar with the Box 1 functionalities, which also allow import and export of full CSAs, e.g., for exchange with other assessors. l Box 2: Use management. Here the uses of the substance are described in a structured way to ensure consistency between use description, the exposure assessments, and the exposure scenario building. The information is presented using Chesar’s life-cycle tree structure, reporting the relevant uses of the substance, considering human health and environmental aspects as well as the tonnage breakdown to the different uses. For each use one environmental contributing scenario is automatically created. Other contributing scenarios for human health and for the environment can be created in addition. The labels (names), the appropriate set of use descriptors according to REACH, and further specifications are included here to be used later on for setting a default conservative exposure assessment. This Chesar element also allows import or export of CSA building blocks (life-cycle tree or parts of it with corresponding exposure assessment). l Box 3: Assessment management. One or more quantitative exposure assessments for each contributing scenario are conducted here. Chesar allows the selection of different exposure assessment methods, while the route/types of effects (for humans) and environmental compartments to be covered have been determined when importing the hazard conclusions from IUCLID in Box 1. Depending on the substance properties and the uses, the plugged in exposure estimation tools could be sufficient or not to demonstrate that the expected exposure is lower than the no-effect thresholds (the DNELs for human effects and the
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PNECs in the case of environmental assessments). Additional assessment methods may be needed in some cases, for example when the uses or the specific use conditions are not covered by the plugged-in tools included in Chesar, or when even after considering all refinement options, Chesar predicts an unacceptable level of risk (exposure exceeding the derived no-effect levels). In such situations other exposure assessment methods or measured data should be included manually to demonstrate a safe use. Alternatively, additional risk management options or significant changes in the operational conditions may be considered. Chesar supports the systematic and transparent manual reporting of such assessments. l Box 4: CSR management. In this part the final exposure scenarios are built by consolidating the assessments carried for the contributing scenarios conducted in Box 3. At this stage hazards without DNELs or PNECs are also taken into account, and appropriate conditions of use are added, if needed to reach a sufficient level of exposure minimization for these hazards. Chesar offers quantitative and qualitative approaches as appropriate for completing the risk characterization. The justifications and final assessment can be clarified by entering explanations on single exposure scenarios or on the overall assessment approach. These explanations will be transferred automatically to the Chemical Safety Report. In Box 4 it is also possible to report risk management measures that are applicable to all uses, and do not result from the exposure assessment carried out for each specific use. l Box 5: SDS ES management. It covers the establishment of the exposure scenarios for communicating the information to downstream users. These scenarios are meant to transport selected parts of the information documented in the Chemical Safety Report to the users. The exposure scenarios are expected to be use-specific and to describe how the substance can be safely used. This includes operational conditions and risk management measures. The scenarios are identified by a short title, which should enable the user of the substance to identify whether the exposure scenario contains information relevant to him. The short titles of the exposure scenarios for a substance shall be consistent with the brief general description of uses in IUCLID. The information should allow downstream users to establish whether or not they work within the conditions for which a safe use has been demonstrated by the registrant in the CSA. (Note that Box 5 is currently not available in Chesar 2.0.) l Box 6: Library management. Box 6 includes the functionalities of the Chesar library. The library enables creation, storage, import, and export of objects that the assessor may need in his Chemical Safety Assessment work process. Chesar 2.0 can manage two library objects: Determinant Types and SpERCs. In the context of Chesar, a ‘Determinant’ is a condition or measure driving the exposure of a substance to man or the environment, for example, the amount of substance used per day at a site, or local exhaust ventilation (LEV) installed at a workplace. A ‘Determinant Type’ is a set of information systematically characterizing a determinant (including metadata) and defining the values it could take. SpERCs are used for environmental
assessments. They correspond to sets of information describing specific conditions of use and the corresponding release estimates (to water, air, soil and waste). These library objects are meant to be used across various assessments, contributing to the harmonization and efficiency of the assessments conducted under REACH. l Box 7: User management. Box 7 covers those aspects related to the user and role management. For example users can use this section for assigning a legal entity to objects created in the library, identifying the author (and therefore the source) of the object.
Exposure Assessments in Chesar The exposure assessment under REACH is required for hazardous substances (those classified according to the CLP/ GHS criteria) and for PBT/vPvB substances. The exposure assessment should present a quantitative or qualitative estimate of the dose/concentration of the substance to which humans and the environment are or may be exposed. The exposure assessment is expected to be an interactive process, but the reporting process for REACH registration is limited to the last step, once the use is considered safe by the registrant, and should include the description of use conditions proposed for ensuring a safe use. Chesar implements these fundamental principles, but may be also used for exchanging preliminary results among registrants and within the supply change. Exposure assessment under REACH includes two elements. The first element is the characterization/definition of the operational conditions and risk management measures for the identified uses; based on this first step, the exposure to humans and to the environment occurring under these conditions should be predicted as a second element of the exposure assessment. The exposure assessment results are used later on during the risk characterization process. Quantitative risk assessments require quantitative exposure estimates, and those are generated in Chesar Box 3. The identification of operational conditions and risk management measures driving this exposure estimation is an essential element for these quantitative exposure assessments. Based on Box 3 results, the final exposure scenarios are built in Box 4, considering also the integration of conditions and measures needed to control risks from hazards for which a qualitative exposure assessment is considered.
Human Exposure Assessment The human exposure assessment estimates the expected exposure for workers and consumers and the indirect exposure via the environment of the general population. For workers, two exposure assessment methods are available, the ECETOC TRA workers v3 method and the exposure assessment based on measured data. In addition, Chesar allows the use of external exposure estimation tools, which results are later manually incorporated to be reported in the CSA. The ECETOC Targeted Risk Assessment (TRA) tool consists of three separate models for estimating exposures to workers, consumers, and the environment that arise during a series of
Chemical Safety Assessment and Reporting Tool (Chesar), REACH
events (ESs). Version 3 of the workers model has been incorporated in Chesar and includes a number of enhancements for increasing the overall accuracy and utility of the ECETOC tool, while still ensuring that the information and skill requirements necessary to develop the associated exposure predictions remain compatible with Tier 1 expectations. The ECETOC TRA workers plugged-in tool covers three routes of exposure: inhalation acute exposure, inhalation longterm exposure, and dermal long-term exposure. In all three cases, local and/or systemic effects can be assessed. In order to run the ECETOC TRA tool, information on the substance properties (e.g., molecular weight, physical state of the substance, vapor pressure if liquid) is needed for estimating the exposure concentrations. The assumptions are defined by the use conditions (e.g., the assigned Product Category (PROC)) and a PROC has to be assigned to the selected contributing scenario. The default exposure assessment with ECETOC TRA workers is based on the conditions of use representing worst case assumptions. Additional information on the ECETOC TRA approach is available in the ECETOC Technical Reports and in the user guidance document. The exposure estimation based on measured data requires the manual introduction for each route of all exposure estimation data (exposure value, units, and explanations on the source and representativity of those values). In addition, the conditions of use associated to the measured data set should be introduced. If the exposure estimates based on measured data will be used as key information for the risk characterization (not just as supportive information), determinant types for the use conditions should be created in the library under Box 6; to ensure that the related conditions of use are part of the ES. Chesar allows the incorporation of exposure estimates obtained using external exposure estimation tools. Commonly used tools (e.g., Stoffenmanager for workers) can be directly selected from a pop-up window, but other tools can be used with a proper explanation. All exposure estimations data (exposure values, units, and explanations on the exposure value if relevant) have to be manually entered for each route. In addition, relevant determinants reporting the conditions of use should be added and transferred to the ES. Standard sets of determinants corresponding to the input parameters of the tool can be used. Chesar allows exposure estimation tool owners to provide sets of determinants in the appropriate Chesar format. Similar exposure assessment methods are considered for consumers estimations, although the ECETOC TRA for consumer is not available in Chesar 2.0 and will be made available in Chesar 2.1. Regarding the indirect human exposure via the environment, these calculations are part of the environmental exposure assessment described as follows.
Environmental Exposure Assessment The environmental protection targets considered in Chesar are aquatic and sediment dwelling organisms (freshwater and marine), predators in the aquatic food chain (freshwater and marine), sewage treatment plant functioning, agricultural soil organisms, predators in the terrestrial food chain, and air. In
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addition, exposure estimates are generated for intakes by humans via the environment, estimating the concentration of substance in air, drinking water, and different food items (e.g., root crops, dairy products, meat, and fish). Chesar allows two complementary assessment types: the ‘Measured Data Assessment’ when there is good quality information on the environmental exposure levels for one or more environmental protection targets, and the ‘EUSES Assessments’ where the exposure is estimated on the basis of selected scenarios. In the EUSES Assessments, exposure concentrations in the different environmental compartments are estimated by combining the expected or measured release rates to water, air, and soil with the EUSES 2.1 fate model. Chesar offers four possibilities for setting the release rates to each environmental compartment: l
Default release estimations based on the Environmental Release Categories (ERC-based release estimations) for any of the release route: water, air, and soil. This is the release method selected by default and corresponds to a worst case estimate of release under the assumption that no specific risk management measures have been put in place. l Targeted estimations based on Specific Environmental Release Category (SpERC-based release estimations) describing the expected release under specific conditions of use and the corresponding release estimates to water, air, soil, and waste, covering all release routes. l Ad hoc release factors for water, air, and/or soil (reported as the percentage of the daily tonnage released to each compartment). An explanation and justification giving details on the source and quality of these release factors must be provided. l Measured release for water and air for the local release rate (kg/day) for each release route. In addition to the release rate, an explanation and justification giving details on the source for these measured release values should be provided. Based on the outcome of these release estimations, Chesar estimates the exposure for the relevant compartments according to the EUSES 2.1 fate model. The EUSES 2.1 fate model uses a set of default parameters and assumptions, which can be modified and adapted to more realistic conditions. The exposure assessment for uses at industrial sites and wide dispersal uses differ from each other, and these conditions are systematically differentiated in Chesar. Uses at industrial sites are assessed for one generic representative site per use. It is assumed that a certain tonnage is used at this one single generic site and that a certain fraction of the use tonnage at this site is released (depending on the conditions of use). As explained above, the release factor depends on the operational conditions and risk management assumed for the generic site. As there may be very large and very small industrial sites for one use, two contributing scenarios (or even the definition of two different uses) may be needed to reflect the difference in conditions and tonnage. By default it is assumed that the discharge from the site is treated in a municipal sewage treatment plant (STP) and the STP sludge is applied to agricultural soil. In addition, it is assumed that the tonnage
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released from the site is diluted in the sewage system and further by an additional dilution factor when the sewage is discharged into the receiving river water. The Chesar plug-in tool has incorporated the default values and assumptions used in the EUSES fate model, these assumptions can be changed in Chesar if needed. For wide dispersal uses it is assumed that the market tonnage is evenly distributed in space and time. The assessment is carried out for a standard town with 10 000 inhabitants and a corresponding use tonnage (fraction of the market tonnage). Thus wide dispersal uses are those uses that correspond to consumer activities, services in a municipality or housing. Depending on the conditions of use, a certain fraction of this tonnage is assumed to be released to the sewage system. It is also assumed that the tonnage released from the 10 000 inhabitants is diluted within the 2000 m3 of wastewater generated by this population (average of 200 l of wastewater per person and day) and then by a generic additional factor of 10 in the receiving river water. By default it is assumed that the STP-sludge is applied to agricultural soil. Usually, the assessor will define one contributing scenario per use and will not overwrite the default assumptions on the local conditions for a substance marketed across Europe. The releases from all uses into the municipal sewage system are aggregated to derive an exposure estimate. The Predicted Environmental Concentrations (PECs) for the generic site or generic town are estimated taking into account the so-called ‘local concentrations’ (Clocal) and ‘regional concentrations.’ The regional concentration results from all the uses of a substance and is calculated by EUSES in the background. The regional concentration is added to the local concentration for deriving the local PEC, in order to take into account that a single site or a single town do not discharge into a virgin environment but just add to emissions released by other site or towns. Measured regional concentrations for one or several compartments can also be reported in Chesar. When measured concentrations are reported they are automatically used as regional concentrations (overwriting the EUSES estimates), and thus also impact on the local PECs for each contributing scenario. Consequently, only very reliable regional concentrations should be reported. For substances considered to be PBT or vPvB, only local concentrations for water are provided. This is due to the large
uncertainties of the regional estimations that should predict the fate, distribution, and long-term effects of such substances in the environment, in particular regarding accumulation in the food chain. Detailed explanations of environmental exposure assessment are available in the Guidance on Information Requirements and Chemical Safety Assessment Chapter R16: Environmental Exposure estimation and in the EUSES user manual and supplementary information.
See also: Society for Chemical Hazard Communication (SCHC); Derived Minimal Effect Level (DMEL); Derived No-Effect Level (DNEL); IUCLID (International Uniform Chemical Information Database); Predicted No Effect Concentration (PNEC); REACH; Chemical Safety Assessment; Risk Management Measures (RMM).
Further Reading ECETOC, 2004. Technical Report No 93: Targeted Risk Assessment. Available at: http://www.ecetoc.org/tra. ECETOC, 2009. Technical Report No 107: Addendum to TR 93(2009). Available at: http://www.ecetoc.org/tra. ECETOC, 2012. Technical Report No 114: ECETOC TRAv3: Background and Rationale for the Improvements. Available at: http://www.ecetoc.org/tra. ECHA, 2008. Guidance on Information Requirements and Chemical Safety Assessment. Available at: http://guidance.echa.europa.eu/guidance_en.htm. ECHA, 2012. Chesar User Manuals. Available at: http://chesar.echa.europa.eu/web/ chesar/support/manuals-tutorials. EC-JRC, 2012. EUSES User Manual. Available at: http://ihcp.jrc.ec.europa.eu/our_ activities/public-health/risk_assessment_of_Biocides/euses/EUSES_2.1/EUSES_2.1_ documentation/EUSES_2.1_User_Manual.pdf.
Relevant Websites http://chesar.echa.europa.eu/ – Chesar, home page. http://www.ecetoc.org/tra – European Centre for Ecotoxicology and Toxicology of Chemicals Target Risk Assessment consumer tool. http://www.ecetoc.org/tra – European Centre for Ecotoxicology and Toxicology of Chemicals Target Risk Assessment worker tool. http://echa.europa.eu – ECHA, European Chemicals Agency. http://ihcp.jrc.ec.europa.eu/our_activities/public-health/risk_assessment_of_Biocides/ euses – European Union System for the Evaluation of Substances, home page.
Introduction The CHEmical Safety Assessment and Reporting tool (Chesar) is an application developed by the European Chemicals Agency (ECHA) to help companies carry out their chemical safety assessments (CSAs) under the European REACH Regulation and to prepare their chemical safety reports (CSRs) that must be included in the REACH registration dossiers and the exposure scenarios (ES) that also should be added to the extended safety data sheets (SDSs) for communication in the supply chain. The CSR is a regulatory requisite that must be included in the registration dossiers for chemicals registered under the REACH Regulation and manufactured or imported above 10 tons per year. Basically, Chesar has implemented as an IT tool the principles related to the CSA as described in the ECHA “Guidance on Information Requirements and Chemical Safety Assessment.” Chesar is directly connected to IUCLID, the electronic database system for storing and presenting the information on the substance identity, its uses, and the hazard information (physical–chemical properties, ecotoxicology, and toxicology end-points). Chesar has been developed as a ‘plugin’ for IUCLID5. Chesar provides a structured workflow for carrying out a standard safety assessment for the different uses of a substance, but provides enough flexibility to accommodate specific situations. The tool also helps to structure the information needed for the exposure assessment and risk characterization, facilitating the generation of a transparent CSR. Chesar allows both quantitative and qualitative risk assessments. The quantitative assessments are based on predicted no-effect levels for human health and for the environment. Under REACH, the predicted no-effect levels for human health assessment are named DNELs, Derived No-Effect Levels, and those for environmental protection, PNECs, Predicted NoEffect Concentrations. Regarding the quantitative exposure assessment, Chesar has combined three complementary generic exposure assessment models, the ECETOC TRA models for workers and for consumers and the EUSES 2.1 fate model for predicting the environmental concentrations. Chesar can also be used in assessments based on other exposure estimation tools or measured data; however, no automated calculation of exposure estimates can be performed in these cases, and the exposure data should be introduced manually. Qualitative risk characterization approaches are used when hazards are identified for a substance but the information does not permit setting predicted no-effect levels. In these cases Chesar supports ES building with qualitative risk characterization. The main aim of Chesar is to increase the efficiency when conducting CSAs under REACH and to provide consistency between CSAs and the information communicated to downstream users, with the automated generation of CSRs and ESs. Chesar facilitates the reuse (or update) of assessment elements generated in Chesar or imported from external
Encyclopedia of Toxicology, Volume 1
sources, and has considered developments by industry, such as generic exposure scenarios (GESs) or specific environmental release categories (SpERCs). It also enables the use of the phrase catalog and the information exchange format for ESs that have been developed under Cefic’s ESCom project.
Chesar Workflows Chesar is divided into seven major groups of functionalities called Boxes. All Boxes are connected and contribute to the generation of the CSR and/or the ES for the extended SDS: l
Box 1: Manage substance. It is used for importing the hazard information from the IUCLIC dossier. This includes the conclusions from the hazard assessment, directly determining the scope of exposure assessment and the type of required risk characterization (qualitative or quantitative). Chesar is used once the hazard assessment according to Annex I of REACH has been finalized, and consequently all the information related to those substances’ intrinsic properties (single end-point summaries and overall toxicological and ecotoxicological summaries) needed for the exposure assessment and risk characterization is available in IUCLID. This information is imported into Chesar with the Box 1 functionalities, which also allow import and export of full CSAs, e.g., for exchange with other assessors. l Box 2: Use management. Here the uses of the substance are described in a structured way to ensure consistency between use description, the exposure assessments, and the exposure scenario building. The information is presented using Chesar’s life-cycle tree structure, reporting the relevant uses of the substance, considering human health and environmental aspects as well as the tonnage breakdown to the different uses. For each use one environmental contributing scenario is automatically created. Other contributing scenarios for human health and for the environment can be created in addition. The labels (names), the appropriate set of use descriptors according to REACH, and further specifications are included here to be used later on for setting a default conservative exposure assessment. This Chesar element also allows import or export of CSA building blocks (life-cycle tree or parts of it with corresponding exposure assessment). l Box 3: Assessment management. One or more quantitative exposure assessments for each contributing scenario are conducted here. Chesar allows the selection of different exposure assessment methods, while the route/types of effects (for humans) and environmental compartments to be covered have been determined when importing the hazard conclusions from IUCLID in Box 1. Depending on the substance properties and the uses, the plugged in exposure estimation tools could be sufficient or not to demonstrate that the expected exposure is lower than the no-effect thresholds (the DNELs for human effects and the
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PNECs in the case of environmental assessments). Additional assessment methods may be needed in some cases, for example when the uses or the specific use conditions are not covered by the plugged-in tools included in Chesar, or when even after considering all refinement options, Chesar predicts an unacceptable level of risk (exposure exceeding the derived no-effect levels). In such situations other exposure assessment methods or measured data should be included manually to demonstrate a safe use. Alternatively, additional risk management options or significant changes in the operational conditions may be considered. Chesar supports the systematic and transparent manual reporting of such assessments. l Box 4: CSR management. In this part the final exposure scenarios are built by consolidating the assessments carried for the contributing scenarios conducted in Box 3. At this stage hazards without DNELs or PNECs are also taken into account, and appropriate conditions of use are added, if needed to reach a sufficient level of exposure minimization for these hazards. Chesar offers quantitative and qualitative approaches as appropriate for completing the risk characterization. The justifications and final assessment can be clarified by entering explanations on single exposure scenarios or on the overall assessment approach. These explanations will be transferred automatically to the Chemical Safety Report. In Box 4 it is also possible to report risk management measures that are applicable to all uses, and do not result from the exposure assessment carried out for each specific use. l Box 5: SDS ES management. It covers the establishment of the exposure scenarios for communicating the information to downstream users. These scenarios are meant to transport selected parts of the information documented in the Chemical Safety Report to the users. The exposure scenarios are expected to be use-specific and to describe how the substance can be safely used. This includes operational conditions and risk management measures. The scenarios are identified by a short title, which should enable the user of the substance to identify whether the exposure scenario contains information relevant to him. The short titles of the exposure scenarios for a substance shall be consistent with the brief general description of uses in IUCLID. The information should allow downstream users to establish whether or not they work within the conditions for which a safe use has been demonstrated by the registrant in the CSA. (Note that Box 5 is currently not available in Chesar 2.0.) l Box 6: Library management. Box 6 includes the functionalities of the Chesar library. The library enables creation, storage, import, and export of objects that the assessor may need in his Chemical Safety Assessment work process. Chesar 2.0 can manage two library objects: Determinant Types and SpERCs. In the context of Chesar, a ‘Determinant’ is a condition or measure driving the exposure of a substance to man or the environment, for example, the amount of substance used per day at a site, or local exhaust ventilation (LEV) installed at a workplace. A ‘Determinant Type’ is a set of information systematically characterizing a determinant (including metadata) and defining the values it could take. SpERCs are used for environmental
assessments. They correspond to sets of information describing specific conditions of use and the corresponding release estimates (to water, air, soil and waste). These library objects are meant to be used across various assessments, contributing to the harmonization and efficiency of the assessments conducted under REACH. l Box 7: User management. Box 7 covers those aspects related to the user and role management. For example users can use this section for assigning a legal entity to objects created in the library, identifying the author (and therefore the source) of the object.
Exposure Assessments in Chesar The exposure assessment under REACH is required for hazardous substances (those classified according to the CLP/ GHS criteria) and for PBT/vPvB substances. The exposure assessment should present a quantitative or qualitative estimate of the dose/concentration of the substance to which humans and the environment are or may be exposed. The exposure assessment is expected to be an interactive process, but the reporting process for REACH registration is limited to the last step, once the use is considered safe by the registrant, and should include the description of use conditions proposed for ensuring a safe use. Chesar implements these fundamental principles, but may be also used for exchanging preliminary results among registrants and within the supply change. Exposure assessment under REACH includes two elements. The first element is the characterization/definition of the operational conditions and risk management measures for the identified uses; based on this first step, the exposure to humans and to the environment occurring under these conditions should be predicted as a second element of the exposure assessment. The exposure assessment results are used later on during the risk characterization process. Quantitative risk assessments require quantitative exposure estimates, and those are generated in Chesar Box 3. The identification of operational conditions and risk management measures driving this exposure estimation is an essential element for these quantitative exposure assessments. Based on Box 3 results, the final exposure scenarios are built in Box 4, considering also the integration of conditions and measures needed to control risks from hazards for which a qualitative exposure assessment is considered.
Human Exposure Assessment The human exposure assessment estimates the expected exposure for workers and consumers and the indirect exposure via the environment of the general population. For workers, two exposure assessment methods are available, the ECETOC TRA workers v3 method and the exposure assessment based on measured data. In addition, Chesar allows the use of external exposure estimation tools, which results are later manually incorporated to be reported in the CSA. The ECETOC Targeted Risk Assessment (TRA) tool consists of three separate models for estimating exposures to workers, consumers, and the environment that arise during a series of
Chemical Safety Assessment and Reporting Tool (Chesar), REACH
events (ESs). Version 3 of the workers model has been incorporated in Chesar and includes a number of enhancements for increasing the overall accuracy and utility of the ECETOC tool, while still ensuring that the information and skill requirements necessary to develop the associated exposure predictions remain compatible with Tier 1 expectations. The ECETOC TRA workers plugged-in tool covers three routes of exposure: inhalation acute exposure, inhalation longterm exposure, and dermal long-term exposure. In all three cases, local and/or systemic effects can be assessed. In order to run the ECETOC TRA tool, information on the substance properties (e.g., molecular weight, physical state of the substance, vapor pressure if liquid) is needed for estimating the exposure concentrations. The assumptions are defined by the use conditions (e.g., the assigned Product Category (PROC)) and a PROC has to be assigned to the selected contributing scenario. The default exposure assessment with ECETOC TRA workers is based on the conditions of use representing worst case assumptions. Additional information on the ECETOC TRA approach is available in the ECETOC Technical Reports and in the user guidance document. The exposure estimation based on measured data requires the manual introduction for each route of all exposure estimation data (exposure value, units, and explanations on the source and representativity of those values). In addition, the conditions of use associated to the measured data set should be introduced. If the exposure estimates based on measured data will be used as key information for the risk characterization (not just as supportive information), determinant types for the use conditions should be created in the library under Box 6; to ensure that the related conditions of use are part of the ES. Chesar allows the incorporation of exposure estimates obtained using external exposure estimation tools. Commonly used tools (e.g., Stoffenmanager for workers) can be directly selected from a pop-up window, but other tools can be used with a proper explanation. All exposure estimations data (exposure values, units, and explanations on the exposure value if relevant) have to be manually entered for each route. In addition, relevant determinants reporting the conditions of use should be added and transferred to the ES. Standard sets of determinants corresponding to the input parameters of the tool can be used. Chesar allows exposure estimation tool owners to provide sets of determinants in the appropriate Chesar format. Similar exposure assessment methods are considered for consumers estimations, although the ECETOC TRA for consumer is not available in Chesar 2.0 and will be made available in Chesar 2.1. Regarding the indirect human exposure via the environment, these calculations are part of the environmental exposure assessment described as follows.
Environmental Exposure Assessment The environmental protection targets considered in Chesar are aquatic and sediment dwelling organisms (freshwater and marine), predators in the aquatic food chain (freshwater and marine), sewage treatment plant functioning, agricultural soil organisms, predators in the terrestrial food chain, and air. In
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addition, exposure estimates are generated for intakes by humans via the environment, estimating the concentration of substance in air, drinking water, and different food items (e.g., root crops, dairy products, meat, and fish). Chesar allows two complementary assessment types: the ‘Measured Data Assessment’ when there is good quality information on the environmental exposure levels for one or more environmental protection targets, and the ‘EUSES Assessments’ where the exposure is estimated on the basis of selected scenarios. In the EUSES Assessments, exposure concentrations in the different environmental compartments are estimated by combining the expected or measured release rates to water, air, and soil with the EUSES 2.1 fate model. Chesar offers four possibilities for setting the release rates to each environmental compartment: l
Default release estimations based on the Environmental Release Categories (ERC-based release estimations) for any of the release route: water, air, and soil. This is the release method selected by default and corresponds to a worst case estimate of release under the assumption that no specific risk management measures have been put in place. l Targeted estimations based on Specific Environmental Release Category (SpERC-based release estimations) describing the expected release under specific conditions of use and the corresponding release estimates to water, air, soil, and waste, covering all release routes. l Ad hoc release factors for water, air, and/or soil (reported as the percentage of the daily tonnage released to each compartment). An explanation and justification giving details on the source and quality of these release factors must be provided. l Measured release for water and air for the local release rate (kg/day) for each release route. In addition to the release rate, an explanation and justification giving details on the source for these measured release values should be provided. Based on the outcome of these release estimations, Chesar estimates the exposure for the relevant compartments according to the EUSES 2.1 fate model. The EUSES 2.1 fate model uses a set of default parameters and assumptions, which can be modified and adapted to more realistic conditions. The exposure assessment for uses at industrial sites and wide dispersal uses differ from each other, and these conditions are systematically differentiated in Chesar. Uses at industrial sites are assessed for one generic representative site per use. It is assumed that a certain tonnage is used at this one single generic site and that a certain fraction of the use tonnage at this site is released (depending on the conditions of use). As explained above, the release factor depends on the operational conditions and risk management assumed for the generic site. As there may be very large and very small industrial sites for one use, two contributing scenarios (or even the definition of two different uses) may be needed to reflect the difference in conditions and tonnage. By default it is assumed that the discharge from the site is treated in a municipal sewage treatment plant (STP) and the STP sludge is applied to agricultural soil. In addition, it is assumed that the tonnage
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released from the site is diluted in the sewage system and further by an additional dilution factor when the sewage is discharged into the receiving river water. The Chesar plug-in tool has incorporated the default values and assumptions used in the EUSES fate model, these assumptions can be changed in Chesar if needed. For wide dispersal uses it is assumed that the market tonnage is evenly distributed in space and time. The assessment is carried out for a standard town with 10 000 inhabitants and a corresponding use tonnage (fraction of the market tonnage). Thus wide dispersal uses are those uses that correspond to consumer activities, services in a municipality or housing. Depending on the conditions of use, a certain fraction of this tonnage is assumed to be released to the sewage system. It is also assumed that the tonnage released from the 10 000 inhabitants is diluted within the 2000 m3 of wastewater generated by this population (average of 200 l of wastewater per person and day) and then by a generic additional factor of 10 in the receiving river water. By default it is assumed that the STP-sludge is applied to agricultural soil. Usually, the assessor will define one contributing scenario per use and will not overwrite the default assumptions on the local conditions for a substance marketed across Europe. The releases from all uses into the municipal sewage system are aggregated to derive an exposure estimate. The Predicted Environmental Concentrations (PECs) for the generic site or generic town are estimated taking into account the so-called ‘local concentrations’ (Clocal) and ‘regional concentrations.’ The regional concentration results from all the uses of a substance and is calculated by EUSES in the background. The regional concentration is added to the local concentration for deriving the local PEC, in order to take into account that a single site or a single town do not discharge into a virgin environment but just add to emissions released by other site or towns. Measured regional concentrations for one or several compartments can also be reported in Chesar. When measured concentrations are reported they are automatically used as regional concentrations (overwriting the EUSES estimates), and thus also impact on the local PECs for each contributing scenario. Consequently, only very reliable regional concentrations should be reported. For substances considered to be PBT or vPvB, only local concentrations for water are provided. This is due to the large
uncertainties of the regional estimations that should predict the fate, distribution, and long-term effects of such substances in the environment, in particular regarding accumulation in the food chain. Detailed explanations of environmental exposure assessment are available in the Guidance on Information Requirements and Chemical Safety Assessment Chapter R16: Environmental Exposure estimation and in the EUSES user manual and supplementary information.
See also: Society for Chemical Hazard Communication (SCHC); Derived Minimal Effect Level (DMEL); Derived No-Effect Level (DNEL); IUCLID (International Uniform Chemical Information Database); Predicted No Effect Concentration (PNEC); REACH; Chemical Safety Assessment; Risk Management Measures (RMM).
Further Reading ECETOC, 2004. Technical Report No 93: Targeted Risk Assessment. Available at: http://www.ecetoc.org/tra. ECETOC, 2009. Technical Report No 107: Addendum to TR 93(2009). Available at: http://www.ecetoc.org/tra. ECETOC, 2012. Technical Report No 114: ECETOC TRAv3: Background and Rationale for the Improvements. Available at: http://www.ecetoc.org/tra. ECHA, 2008. Guidance on Information Requirements and Chemical Safety Assessment. Available at: http://guidance.echa.europa.eu/guidance_en.htm. ECHA, 2012. Chesar User Manuals. Available at: http://chesar.echa.europa.eu/web/ chesar/support/manuals-tutorials. EC-JRC, 2012. EUSES User Manual. Available at: http://ihcp.jrc.ec.europa.eu/our_ activities/public-health/risk_assessment_of_Biocides/euses/EUSES_2.1/EUSES_2.1_ documentation/EUSES_2.1_User_Manual.pdf.
Relevant Websites http://chesar.echa.europa.eu/ – Chesar, home page. http://www.ecetoc.org/tra – European Centre for Ecotoxicology and Toxicology of Chemicals Target Risk Assessment consumer tool. http://www.ecetoc.org/tra – European Centre for Ecotoxicology and Toxicology of Chemicals Target Risk Assessment worker tool. http://echa.europa.eu – ECHA, European Chemicals Agency. http://ihcp.jrc.ec.europa.eu/our_activities/public-health/risk_assessment_of_Biocides/ euses – European Union System for the Evaluation of Substances, home page.