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In this study, 129 exposure situations (ESs) with six or more measured inhalation exposures to dust from solids or vapour from liquids in occupational settings were compared with modelled European Centre of Ecotoxicology and Toxicology of Chemicals (ECETOC) targeted risk assessment tool, version 3 (TRAv3) estimates. The measurement data were extracted from previously published studies examining TRAv3 performance and pooled into a curated database. The comparison exercise focussed on the vapour exposure scenarios, as there were too few dust scenarios for a meaningful analysis of any required model corrections. A group of experts in the exposure modelling field retrieved and reviewed the input parameters used in these ESs. Where considered appropriate, modifications were applied to better match the input parameter definitions and the scope of applicability of the TRAv3. Differences and mean absolute error (MAE) were calculated between the log-transformed modelled exposure value and the 75th percentile of each measured data set and regression analysis was performed. The results indicated that the TRAv3 overestimated 80% of the measured data sets. Both over- and underestimations were mostly by factors 1–5. The calculated MAE for liquids was 0.7, indicating that on average the difference between the 75th percentile and the TRAv3 estimate was less than one order of magnitude. A multiple linear regression showed that some input parameters such as medium volatility, certain process categories (PROC), industrial setting, and the presence of local exhaust ventilation are associated with underestimations. The results of the regression analysis can be used by TRAv3 users to review the degree of over- or underestimation in their current exposure assessments, compared to the curated database. Although multiple linear regression is an appropriate methodology to characterize the TRAv3’s performance, more data sets are still needed in view of some remaining data gaps. Nevertheless, the results of the current analysis are being used by ECETOC to further develop the tool as a suitably conservative screening tool for use in REACH chemical safety assessment of occupational exposure to chemicals.

Background The European Centre for Ecotoxicology and Toxicology of Chemicals (ECETOC) Targeted Risk Assessment (TRA) Consumer tool was developed to fill in a methodology gap for a high throughput, screening level tool to support industry compliance with the European Union’s Registration, Evaluation, Authorization, and Restriction of Chemicals (REACH) regulation. Objective To evaluate if the TRA Consumer tool has met its design of being a screening level tool (i.e., one which does not under-predict potential exposures). Methods The TRA Consumer tool algorithms and defaults were reviewed and performance benchmarked vs. other consumer models and/or empirical data. Findings from existing reviews of the TRA consumer tool were also considered and addressed. Results TRA predictions based on its default inputs exceeded measured exposures when available, typically by orders of magnitude, and were generally greater than or similar to those of other consumer exposure tools. For dermal exposure from articles, there was no evidence that a diffusivity approach would provide more appropriate exposure estimates than those of the TRA. When default values are refined using more specific data, the refined values must be considered holistically to reflect the situation being modeled as some parameters may be correlated. Significance This is the first evaluation of the ECETOC TRA consumer tool in its entirety, considering algorithms, input defaults, and associated predictions for consumer products and articles. The evaluation confirmed its design as a screening level tool. Impact Statement The ECETOC TRA Consumer tool has been widely applied to generate exposure estimates to support chemical registrations under the EU REACH regulation. This evaluation supports the appropriateness of the TRA as a screening level exposure assessment tool. It also warrants additional measurements of consumer exposure, especially for article use scenarios, to aid the development of consumer exposure tools and chemical risk assessment.

The Targeted Risk Assessment tool (TRA) has been widely used since 2010 in the development of REACH registration dossiers for classified chemical substances to estimate worker exposures (inhalation, dermal) across manufacturing and use operations in supply chains in Europe. The TRA is a Tier-1 tool which produces simplified exposure predictions based on limited inputs and intended to be conservative. The current version (3.1) of the TRA was released in 2012 and has been built into ECHA’s CHESAR tool. A number of studies have been published of TRA-generated exposure predictions compared with workplace measurement data and presenting conclusions about the tool performance. Most publications covered only a subset of the tool outputs. A group of ECETOC exposure assessors assembled inventories of published comparisons over the period of 2010-2020 (approximately 120 workplace scenarios for long-term inhalation, 40 scenarios for peak inhalation and 80 scenarios for dermal exposure) to systematically review the tool performance. The analysis has allowed to draw more robust conclusions about the performance of specific aspects of the tool, such as base level estimates and effectiveness of local exhaust ventilation, to either reinforce the conclusions of conservatism (majority of scenarios) or recommend changes to tool settings in a future version (minority of cases) to better match the tool’s intent. A short overview of the comparisons will be presented, as well as the planned changes to the tool settings.

(1) Background: The ECETOC Targeted Risk Assessment (TRA) tool is widely used for estimation of worker exposure levels in the development of dossiers for REACH registration of manufactured or imported chemical substances in Europe. A number of studies have been published since 2010 in which the exposure estimates of the tool are compared with workplace exposure measurement results and in some instances an underestimation of exposure was reported. The quality and results of these studies are being reviewed by ECETOC. (2) Methods: Original exposure measurement data from published comparison studies for which six or more data points were available for each workplace scenario and a TRA estimate had been developed to create a curated database to examine under what conditions and for which applications the tool is valid or may need adaptation. (3) Results: The published studies have been reviewed for completeness and clarity and TRA estimates have been constructed based on the available information, following a set of rules. The full review findings are expected to be available in the course of 2021. (4) Conclusions: The ECETOC TRA tool developers periodically review the validity and limitations of their tool, in line with international recommendations.

The process for undertaking exposure assessments varies dependent on its purpose. But for exposure assessments to be relevant and accurate, they are reliant on access to reliable information on key exposure determinants. Acquiring such information is seldom straightforward and can take significant time and resources. This articles examines how the application of tiered and targeted approaches to information acquisition, within the context of European human health risk assessments, can not only lead to improvements in the efficiency and effectiveness of the process but also in the confidence of stakeholders in its outputs. The article explores how the benefits might be further improved through the coordination of such activities, as well as those areas that represent barriers to wider international harmonisation.

The ability to measure chemicals in humans (often termed biomonitoring) is far outpacing the ability to interpret reliably these data for public health purposes, creating a major knowledge gap. Until this gap is filled, the great promise of routinely using biomonitoring data to support decisions to protect public health cannot be realized. Research is needed to link biomonitoring data quantitatively to the potential for adverse health risks, either through association with health outcomes or using information on the concentration and duration of exposure, which can then be linked to health guidelines. Developing such linkages in the risk assessment paradigm is one of the primary goals of the International Council of Chemical Associations' (ICCA) Long-Range Research Initiative (LRI) program in the area of biomonitoring. Therefore, ICCA sponsored a workshop to facilitate development of a coordinated agenda for research to enable an improved interpretation of human biomonitoring data. Discussions addressed three main topics: (1) exploration of the link between exposure, dose, and human biomonitoring data, (2) the use of computational tools to interpret biomonitoring data, and (3) the relevance of human biomonitoring data to the design of toxicological studies. Several overarching themes emerged from the workshop: (a) Interpretation and use of biomonitoring data should involve collaboration across all sectors (i.e., industry, government, and academia) and countries. (b) Biomonitoring is not a stand-alone tool, and it should be linked to exposure and toxicological dose information. (c) Effective communication is critical, because when uncertainty about the actual risks is high, the perceived risks grow in the absence of communication. (d) The scope of future biomonitoring activities encompasses a variety of research approaches — from advancing the science to fill data gaps to advancing the accessibility of the current knowledge to enable better information sharing.

ECETOC has been developed an approach by which the health and environmental risks arising from the supply and use of chemicals can be quickly and reliably evaluated by chemical suppliers. The approach has been available as a web-based tool since 2004. During the development and implementation of the approach, ECETOC has consulted widely so that the approach is seen to meet the required levels of science while also meeting the differing needs of affected stakeholders. The consultation process has yielded a number of findings in terms of the considerations necessary for implementing successful risk-informed decision-making in a multi-stakeholder environment. Concurrently, as the European Commission's REACH legislative package has begun to take shape, it has also become apparent that the approach has a number of potential applications for aiding the process of risk assessment under REACH. This paper reviews these experiences within the broader context of the expectations that REACH places on chemical manufacturers and suppliers. In particular, it highlights the key role that REACH Exposure Scenarios have for evaluating, managing and communicating chemical risks.

In order to respond to the increasing need for chemical suppliers to evaluate effectively and consistently the likely risks to health that the use of chemicals at work might present, the European Centre for Ecotoxicology and Toxicology of Chemicals has developed a tiered approach to this challenge. It builds on concepts that are already in use in some areas of workplace health and safety but, uniquely, applies them in the context of the chemicals supply chain. The approach applies these concepts in a series of tiers, in order to target, with increasing certainty, those situations that present a potential risk to human health. Adopting such an approach provides an ability to align the responsibilities and expectations of employers more closely with those of chemicals suppliers.This paper provides an overview of the approach and, specifically, a detailed commentary on the process used to evaluate workplace risks arising from the use of chemicals. It provides evidence, based on a limited validation e...

The ECETOC Targeted Risk Assessment (TRA) model is intended to evaluate the nature of human and environmental exposures and risks arising from the manufacture and use of chemicals and version 2 has been extensively applied to develop Chemical Safety Assessments for substances registered under Phase 1 of REACH. In order to maintain the model, ECETOC solicited suggestions from TRA users arising from their experiences gained from its use in the 2009–2011 period. TRA users identified 16 different ways in which the worker exposure predictions of the TRA might be further improved at the technical level. The suggestions can be divided into those that are capable of being incorporated into the model and those which cannot which, in turn, appear to be reflective of the wide range of technical understandings of users of Tier 1 REACH models such as the TRA. The consequence of such user heterogeneity presents challenges for model developers, particularly those models intended for inclusion in regulatory processes. Those considerations that are relevant for the revision to the worker portion of the TRA (version 3) are described, together with their potential relevance for other REACH exposure models.

An approach is described for how the quality of human data can be systematically assessed and categorised. The approach mirrors the animal data quality considerations set out by Klimisch et al., in order that human data quality can be addressed in a complementary manner and to help facilitate transparent (and repeatable) weight of evidence comparisons. Definitions are proposed for the quality and adequacy of data. Quality is differentiated into four categories. A description of how the scheme can be used for evaluating data reliability, especially for use when contributing entries to the IUCLID database, is shown. A discussion of how the criteria might also be used when determining overall data relevance is included. The approach is intended to help harmonise human data evaluation processes worldwide.

The European Solvents Industry Group (ESIG) Generic Exposure Scenario (GES) Risk and Exposure Tool (EGRET) was developed to facilitate the safety evaluation of consumer uses of solvents, as required by the European Union Registration, Evaluation and Authorization of Chemicals (REACH) Regulation. This exposure-based risk assessment tool provides estimates of both exposure and risk characterization ratios for consumer uses. It builds upon the consumer portion of the European Center for Ecotoxicology and Toxicology of Chemicals (ECETOC) Targeted Risk Assessment (TRA) tool by implementing refinements described in ECETOC TR107. Technical enhancements included the use of additional data to refine scenario defaults and the ability to include additional parameters in exposure calculations. Scenarios were also added to cover all frequently encountered consumer uses of solvents. The TRA tool structure was modified to automatically determine conditions necessary for safe use. EGRET reports results using specific standard phrases in a format consistent with REACH exposure scenario guidance, in order that the outputs can be readily assimilated within safety data sheets and similar information technology systems. Evaluation of tool predictions for a range of commonly encountered consumer uses of solvents found it provides reasonable yet still conservative exposure estimates.

The European Union Registration, Evaluation, Authorization, and Restriction of Chemicals (REACH) Regulation (EC 1907/2006) places significant new obligations on the manufacturers or importers (M/Is) of chemicals in Europe. It also places new responsibilities on downstream users (DUs) of these chemicals i.e. those that purchase and use chemical products. In particular, for registered classified substances, the M/I is expected to communicate how any substance can be safely used without risk to man or the environment. This communication is in the form of an exposure scenario (ES), which is included in an Annex to the REACH extended safety data sheet. DUs then have certain obligations relating to adopting the control conditions described in the ES. The REACH Technical Guidance Documents lay down the expectations for the process of risk assessment that M/Is should adopt when developing ESs. But with many thousands of chemicals in daily commerce, it is also necessary to ensure that what is communicated to DUs not only meets the requirements of REACH but is also understandable to these groups, as well as being consistent across different chemical suppliers and supply chains. In cooperation with relevant DU groups, the European solvents industry has developed generic approaches for describing how solvents are commonly used, in order that these can subsequently be used as the basis for REACH registrations and related safety data sheet communications on health risk control. The utility of these approaches (termed 'generic exposure scenarios') is acknowledged under REACH and they are now publicly available for use both by M/Is and DUs.

The incorporation of human experience data (HD) into the risk assessment process is encouraged by various authorities with the aim of improving the robustness of the subsequent findings. HD, however, can present in many forms, ranging from epidemiological studies to the accumulated experiences from poison centers. This diversity of the human experience, combined with the manner in which it may (or may not) present, creates several challenges for risk assessors if they are to give available HD due weight in the RA process. An evaluation was made of how HD has been cited and used within the 64 human health RAs published by the EU to the end of 2005. In all RAs, HD had been cited to some degree. But there was no consistency between how cited data had subsequently been taken forward and used in the evaluation of different endpoints, either between the RAs authored by the same or different EU Member States. The lack of any accepted guidance for addressing the role that HD can play within the RA process appears to lead to this situation. Recommendations are provided on the scope and focus such guidance could usefully be expected to take.

The primary process established by the European Commission to address the science needed to define key REACH concepts and to help rationally implement REACH's ambitions is enshrined in a series of activities known as the REACH Implementation Projects (RIPs). These are projects that aim to define the methodology that could be used, and present the basis for guidance on the actual principles and procedures that may be (are proposed to be) followed in the development of the required documentation that ensures the safe use of chemicals. In order to develop soundly based and equitable regulation, it is necessary that science governance using established and accepted scientific principles must take a leading role. The extent to which such governance is embraced will be determined by many factors, but notably the process adopted to enable scientific discussion to take place. This article addresses the issues of science as they have impacted on the exemplification of the Exposure Scenario concept under REACH. The current RIP activities have created a non-adversarial process in which the key stakeholders are able to discuss the key REACH challenges. But the RIP activities will be finalised before REACH comes into force. A suitable mechanism should perhaps now be identified to ensure that this positive spirit of scientific discussion and collaboration can continue to benefit REACH and those that it serves well into the future. © 2007 Nature Publishing Group All rights reserved.

The new European chemicals legislation REACH (Registration, Evaluation, Authorisation and restriction of Chemicals) requires the development of Exposure Scenarios describing the conditions and risk management measures needed for the safe use of chemicals. Such Exposure Scenarios should integrate considerations of both human health and the environment. Specific aspects are relevant for worker exposure. Gathering information on the uses of the chemical is an important step in developing an Exposure Scenario. In-house information at manufacturers is an important source. Downstream users can contribute information through direct contact or through their associations. Relatively simple approaches (Tier 1 tools, such as the ECETOC Targeted Risk Assessment and the model EASE) can be used to develop broad Exposure Scenarios that cover many use situations. These approaches rely on the categorisation of just a few determinants, including only a small number of risk management measures. Such approaches have a limited discriminatory power and are rather conservative. When the hazard of the substance or the complexity of the exposure situation require a more in-depth approach, further development of the Exposure Scenarios with Tier 2 approaches is needed. Measured data sets of worker exposure are very valuable in a Tier 2 approach. Some downstream user associations have attempted to build Exposure Scenarios based on measured data sets. Generic Tier 2 tools for developing Exposure Scenarios do not exist yet. To enable efficient development of the worker exposure part of Exposure Scenarios a further development of Tier 1 and Tier 2 tools is needed. Special attention should be given to user friendliness and to the validity (boundaries) of the approaches. The development of standard worker exposure descriptions or full Exposure Scenarios by downstream user branches in cooperation with manufacturers and importers is recommended. © 2007 Nature Publishing Group All rights reserved.

EASE (Estimation and Assessment of Substance Exposure) is a general model that may be used to predict workplace exposure to a wide range of substances hazardous to health. First developed in the early 1990s, it is now in its second Windows version. This paper provides a critical assessment of the utility and performance of the EASE model, and on the basis of this review, recommendations for the structure of a revised model are outlined. Twenty-seven stakeholders were interviewed about their previous use of EASE, perceived advantages and limitations of the model and suggestions for improvement. A subset of stakeholders was contacted on a second occasion to determine their views on the preferred outputs for an ideal exposure assessment model. Overall, stakeholders felt that the model should be updated to provide more accurate and precise exposure assessments. However, users also expressed the view that the simplicity and usability of the software model should not be compromised. Six studies investigating the validity of the inhalation exposure assessment section of EASE were identified. These showed that the model generally either predicted close to the measured exposures or overestimated exposure; though performance was highly variable. Two studies investigated the validity of the dermal exposure assessment and found that EASE produced considerable overestimates of actual dermal exposure (the amount of a substance that actually lands on the skin). A conceptual model of exposure was developed to investigate whether the structure of the EASE model is appropriate. Although EASE has a number of characteristics that describe exposure, it is a greatly simplified model and does not include all the important exposure determinants. More importantly, EASE can produce estimates of exposure that are ambiguous or incomplete. Our conceptual model may provide a rational basis for developing an improved version of EASE but further consultation is needed to decide the purpose and intended use of any successor to EASE.

In recent years, several approaches have been proposed for the application of control banding concepts to the assessment and management of various workplace health and safety risks. Whilst many of the earlier approaches have originated in the UK, several of the most recent examples have been developed in Europe. The European schemes have attempted to build upon the lessons learned from the earlier control banding schemes and to apply them to new areas of health and safety. This paper analyses the evolution of the earlier approaches and reviews the more recent European developments in the context of continuing regulatory and societal demands for the improved assessment and regulation of workplace chemical risks.

The process of risk assessment for human health demands the availability of soundly based effects and exposure information. However, many of the available data, particularly those which seek to describe human exposures to chemicals, are of varying quality and scope. Changing public and regulatory expectations increasingly demand that the outcomes of risk assessments are seen to have duly accounted for these data, in order that their conclusions can be viewed as valid. The challenge for risk assessors, therefore, is how the different grades of data should be integrated within the overall process. A series of core values are identified that govern the relationships and the influence that different types of exposure data have within European Union (EU) regulatory risk assessment for chemicals. Building on these values, an approach is presented for evaluating workplace exposure information in the context of how such data might be used within the EU process for assessing the risks to human health of new and existing substances. The implications of adopting the approach for regulatory risk assessment within the EU and its consequent impact on current occupational hygiene practice are discussed.

Biomonitoring, the determination of chemical substances in human body fluids or tissues, is more and more frequently applied. At the same time detection limits are decreasing steadily. As a consequence, many data with potential relevance for public health are generated although they need not necessarily allow interpretation in term of health relevance. The European Centre of Ecotoxicology and Toxicology of Chemicals (ECETOC) formed a dedicated task force to build a framework for the interpretation of biomonitoring data. The framework that was developed evaluates biomonitoring data based on their analytical integrity, their ability to describe dose (toxicokinetics), their ability to relate to effects, and an overall evaluation and weight of evidence analysis. This framework was subsequently evaluated with a number of case studies and was shown to provide a rational basis to advance discussions on human biomonitoring allowing better use and application of this type of data in human health risk assessment.

In the last two decades, sustainable and safe use of chemicals became a focal point of various international policy efforts and has been addressed through launching of chemical management systems worldwide. In the EU, the regulation on Registration, Evaluation and Authorization of Chemicals (REACH) primarily concentrates on generating substance intrinsic properties data (including hazard) depending on the tonnage being registered. However, using the chemical production/import volume alone as a proxy/indicator of true exposures undermines risk management decision making and deprives exposure information of its real power (e.g. smart studies design, more efficient prioritization). The European Centre for Ecotoxicology and Toxicology of Chemicals (ECETOC) together with the European Chemical Industry Council Long Range Initiative program streamline their research efforts towards gaining wider regulatory acceptance of exposure-informed testing and risk management practices. This presentation provides an overview of recent industry-funded research building a knowledgebase on tools and methods for assessment of low exposure. The problem definition of low exposure in various contexts will be discussed, focusing on aspects/factors that make low exposure very important in certain situations. A detailed outline will be provided for multiple projects that consider low exposure from differentperspectives. The examples will cover comparative exposure analysis of alternative exposure sources to the same substance, assessment of intentional and non-intentional exposure, exposure based waiving and workplace risk assessment. The presented material should inform the workshop participants about the ECETOC’s perspective on the importance/weight of (low) exposure in regulatory risk assessment and set the stage for a follow-up panel discussion to help identify remaining knowledge gaps and future focus areas.

Biomonitoring, the determination of chemical substances in human body fluids or tissues, is more and more frequently applied. At the same time detection limits are decreasing steadily. As a consequence, many data with potential relevance for public health are generated although they need not necessarily allow interpretation in term of health relevance. The European Centre of Ecotoxicology and Toxicology of Chemicals (ECETOC) formed a dedicated task force to build a framework for the interpretation of biomonitoring data. The framework that was developed evaluates biomonitoring data based on their analytical integrity, their ability to describe dose (toxicokinetics), their ability to relate to effects, and an overall evaluation and weight of evidence analysis. This framework was subsequently evaluated with a number of case studies and was shown to provide a rational basis to advance discussions on human biomonitoring allowing better use and application of this type of data in human health risk assessment.