Feasibility of validating the Uniform System for the Evaluation of Substances (USES)
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Series / Report no.
Open Access
Type
Report
Language
en
Date
1995-01-31
Research Projects
Organizational Units
Journal Issue
Title
Feasibility of validating the Uniform System for the Evaluation of Substances (USES)
Translated Title
Haalbaarheid van validatie van het Uniforme Beoordelingssysteem Stoffen (UBS)
Published in
Abstract
UBS, het Uniforme Beoordelingssysteem Stoffen, is een beslissings-ondersteunend gereedschap voor een snelle, kwantitatieve analyse van de risico's verbonden aan de levenscyclus van een chemische stof. Omdat risico-analyse een inherent onzeker proces is, is een grondige modelanalyse aan te bevelen. Een vorige versie van UBS was slechts gedeeltelijk gevalideerd, wat onvoldoende was voor een volledige validatie. Risico's kunnen niet in het veld gemeten worden, daarom zal de aandacht voornamelijk gericht zijn op validatie van de afzonderlijke modellen en modulen van UBS. Dit rapport beschrijft de procedure die gevolgd kan worden om de gebruiker te tonen wat de nauwkeurigheidsgraad is die UBS kan geven. Dit geeft de beleidsmaker de mogelijkheid om de nauwkeurigheid van UBS bij risico-analyse in overweging te nemen. In dit rapport wordt de validatie-status van de huidige modulen van UBS bediscussieerd. Een kader en aanbevelingen voor toekomstige validatie wordt gegeven. De aannamen en keuzen (vaak impliciet gemaakt) zijn nu geexpliciteerd. Geconcludeerd kan worden dat voor vele modulen numerieke validatie reeds is uitgevoerd of geinitieerd. Operationele validatie van de toepasbaarheid van het gehanteerde model en conceptuele validatie van het blootstellingsscenario ontbreekt echter. Omdat veel van de validatieactiviteiten buiten het kader van het UBS-project plaatsvinden, is inventarisatie van al de resultaten noodzakelijk. Dit rapport beschrijft tevens een experiment om de risicoschattingen van UBS te 'valideren'. Dit gebeurde door prioritering van stoffen door experts te vergelijken met prioritering door UBS. Ondanks vele onzekerheden geeft deze aanpak meer inzicht in de relatie tussen 'objectieve' risico-schatting van UBS en de 'risico-perceptie' van experts. In 1995 en 1996 zal een Europees systeem voor risico-analyse ontwikkeld worden, gebaseerd op de huidige versie van UBS. De inventarisatie en discussie in dit rapport van de huidige modulen en scenario's kan gebruikt worden bij deze ontwikkeling. Een validatie van het huidige UBS is niet gepland. Als het Europese systeem afgerond is kan dit systeem grondig geanalyseerd worden waarbij dit rapport de basis kan vormen.<br>
USES, the Uniform System for Evaluation of Substances, is a decision-supporting tool, that can be used for rapid, quantitative assessment of the hazards and risks of chemical substances. Since risk assessment is an inherently uncertain process, a thorough model analysis is advisable. A previous version of USES was only partially validated, which was not sufficient sofar. Risks cannot be measured in the field, therefore, the effort will be aimed at validating the separate (sub-) modules of USES. This report describes the procedure that can be followed to show the user of the system the degree of accuracy that USES is able to give. This gives decision makers the opportunity to take the accuracy of USES into account in risk assessment. In this report, the validation status of the present modules of USES is discussed. A framework and recommendations for future validation are given. Furthermore, the assumptions and choices for the exposure scenario (often made implicitly) are listed. It was concluded that for many modules, numerical validation has been performed or initiated. Operational validation of the appropriateness of the model chosen, and conceptual validation of the exposure scenario are however, still lacking. Furthermore, since many of the validation activities are performed outside the framework of the USES project, inventarisation of all the results is needed. This report also describes an experiment to 'validate' the risk estimates of USES. This was done by comparing priorities of substances by experts to the ranking of USES. Despite many limitations, this approach gives more insight in the relation between the 'objective' risk estimate of USES and experts 'risk perception'. In 1995 and 1996, a European risk assessment system will be developed, based on the present version of USES. The inventarisation and discussion in this report of the present modules and scenarios can be used in this development. Validation of the present version of USES is not planned. When the European risk assessment system is finalised, this system can be thoroughly analyzed, using this report as a basis.<br>
USES, the Uniform System for Evaluation of Substances, is a decision-supporting tool, that can be used for rapid, quantitative assessment of the hazards and risks of chemical substances. Since risk assessment is an inherently uncertain process, a thorough model analysis is advisable. A previous version of USES was only partially validated, which was not sufficient sofar. Risks cannot be measured in the field, therefore, the effort will be aimed at validating the separate (sub-) modules of USES. This report describes the procedure that can be followed to show the user of the system the degree of accuracy that USES is able to give. This gives decision makers the opportunity to take the accuracy of USES into account in risk assessment. In this report, the validation status of the present modules of USES is discussed. A framework and recommendations for future validation are given. Furthermore, the assumptions and choices for the exposure scenario (often made implicitly) are listed. It was concluded that for many modules, numerical validation has been performed or initiated. Operational validation of the appropriateness of the model chosen, and conceptual validation of the exposure scenario are however, still lacking. Furthermore, since many of the validation activities are performed outside the framework of the USES project, inventarisation of all the results is needed. This report also describes an experiment to 'validate' the risk estimates of USES. This was done by comparing priorities of substances by experts to the ranking of USES. Despite many limitations, this approach gives more insight in the relation between the 'objective' risk estimate of USES and experts 'risk perception'. In 1995 and 1996, a European risk assessment system will be developed, based on the present version of USES. The inventarisation and discussion in this report of the present modules and scenarios can be used in this development. Validation of the present version of USES is not planned. When the European risk assessment system is finalised, this system can be thoroughly analyzed, using this report as a basis.<br>
Description
Publisher
Rijksinstituut voor Volksgezondheid en Milieu RIVM
Sponsors
DGM/SVS