Development of a mechanistic model for the Advanced REACH Tool (ART).

The ART project comprises of several main components; i.e. development of a mechanistic
model, Bayesian model, exposure database, software development, and testing and validation.
This report will focus on the development of the mechanistic model. The conceptual model
development as well as characterization of the principal MF is described in this report, whereas its
calibration with exposure measurements will be described separately.
The mechanistic model development started with a conceptual framework (Tielemans et al.,
2008a). This framework defines the principal modifying factors (MF) and provides a methodology
for clustering occupational activities into Activity Classes. This chapter also classifies the various
types of products that can be handled (e.g. powders, volatile liquids, etc.) and exposure forms
(e.g., dusts, vapours, aerosols, etc.) that can result from handling these products. A detailed
description of the principal MF and underlying determinants is given in chapter 3. This also
resulted in the assignment of relative scores to the various categories of the principal MF. Chapter
4 provides an overall overview of the workflow of the mechanistic model. Finally, in chapter 5
conclusions are drawn and recommendations given for future use and development. Various parts
of this report are, or will be published as separate papers in the peer reviewed literature.