Evaluation of Tier 1 Exposure Assessment Models under REACH (eteam) Project - Final Overall Project Summary Report

The Tier 1 exposure tools ECETOC TRA, MEASE, STOFFENMANAGER, EMKG-EXPO-TOOL and RISKOFDERM used for REACH are designed to be simple and easy to use by a range of assessors and to provide conservative estimate of exposure. The eteam Project aimed to carry out a comprehensive evaluation of the Tier 1 exposure tools. This report provides a summary of the main results of the evaluation together with the authors' assessment of the main implications. Recommendations are made for tool developers, users and regulators. The project incorporated a range of qualitative and quantitative evaluation methods in the different work packages. These methods are detailed in the accompanying deliverable reports.

The tools differ in their underlying basis and in the number and definition of a limited range of input parameters. The tools were considered to be user-friendly and easy to access, download and use. However, extremely large variability was observed in outputs generated by a group of representative tool users (n=146) when assessing identical exposure situations. A small number of input parameters drove most of the variation; the task descriptor (PROC code or handling description), risk management measures and type of setting. This type of variability has been identified with all exposure assessment tools involving subjective assessment of parameters. An evaluation of tool uncertainty found that the type and level of uncertainty was heavily dependent on the individual situation being assessed, and should be considered in the context of the overall uncertainty of the exposure assessment process. The uncertainty arising from using Tier 1 tools is designed to be addressed by providing conservative estimates of exposure. Estimates of the tools were generally conservative, but did not always provide estimates that would be considered as a reasonable worst-case (as defined by the 90th percentile of exposure). Correlations between the measurement results and tool predictions were generally stronger for powders and non-volatile liquids than for the other exposure categories.

Comparison with measurement data suggested that the tools were generally conservative, but perhaps not always sufficiently so when compared with the reasonable worst case estimates as defined by the 90th percentiles of the exposure distribution. STOFFENMANAGER appeared to provide the most balanced performance with regard to the level of conservatism and predictive power for volatile liquids and powders. Furthermore, systems should be developed and applied to reduce the extreme levels of variability between users. Tool users must be more aware of the appropriate operation of the tools and their limitations. Improved quality assurance procedures including user certification and round-robin exercises, together with team-based assessments, the application of different models in tandem and corroboration of tool estimates with any available measurement data, should help improve the reliability of all of the tools.

Bibliographic information

Title:  Evaluation of Tier 1 Exposure Assessment Models under REACH (eteam) Project - Final Overall Project Summary Report. 

Written by:  J. Lamb, S. Hesse, B. G. Miller, L. MacCalman, K. Schroeder, J. Cherrie, M. van Tongeren

1. edition.  Dortmund:  Bundesanstalt für Arbeitsschutz und Arbeitsmedizin, 2015. 
ISBN: 978-3-88261-160-1, pages: 169, Project number: F 2303, PDF file

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Further Publications

Evaluation of Tier 1 Exposure Assessment Models under REACH (eteam) Project - Substudy Report on Gathering of Background Information and Conceptual Evaluation

Report 2015

In this part of the eteam Project a general evaluation of the models' concepts was conducted. This included the tools ECETOC TRA (version 2 and 3), MEASE (version 1.02.01), the EMKG-EXPO-TOOL, STOFFENMANAGER® (version 4.5) and RISKOFDERM (version 2.1), but also EASE (version 2), which has been …

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Evaluation of Tier 1 Exposure Assessment Models under REACH (eteam) Project - Substudy Report on External Validation Exercise

Report 2015

Tier 1 assessment tools are used frequently to provide exposure estimates as part of the substance registration process under Regulation (EC) No 1907/2006 (REACH). Using only a limited number of basic input parameters, these generic tools are designed to provide conservative exposure predictions …

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Evaluation of Tier 1 Exposure Assessment Models under REACH (eteam) Project - Substudy Report on User-Friendliness of Tier 1 Exposure Assessment Tools under REACH

Report 2015

Work Package I.6 of the eteam project was developed to evaluate operational aspects of the usability and fitness for purpose of each of the first tier exposure assessment tools included in the project. A series of telephone interviews were carried out with experienced users for each of the tools. …

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Evaluation of Tier 1 Exposure Assessment Models under REACH (eteam) Project - Substudy Report on Between-User Reliability Exercise (BURE) and Workshop

Report 2015

When applying the Tier 1 assessment tools to an exposure situation, users must select options from several possible input parameters. Previous studies have suggested that results from exposure assessments using expert judgement can vary considerably between assessors. In addition, similar results …

To the Publication

Evaluation of Tier 1 Exposure Assessment Models under REACH (eteam) Project - Substudy Report on Uncertainty of Tier 1 Models

Report 2015

In this work package of the eteam project different aspects of the tools were evaluated which may lead to an uncertainty of the model estimate, i.e. a deviation of the estimate from the actual exposure value at a workplace. For this purpose a qualitative approach as suggested by the WHO and the …

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Further stratification of the ETEAM study results

baua: Report 2016

The ETEAM study was an evaluation of several low-tier models commonly used in the estimation of exposure to chemical agents at the workplace. The aim of these low-tier models is to offer simple, but conservative estimates. Amongst others, the study included a validation of the models against …

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Further Information

Research Project

Project numberF 2303 StatusCompleted Project Validation of models for the initial estimation of occupational exposure (Tier 1) in the chemical safety assessment under REACH

To the Project

Research completed