EU-SICHERHEITSDATENBLATT Dieselkraftstoff ... - Schmierstoffe

infinite number of structures including many variations and combinations of the classes
and with increasing boiling point of a petroleum substance, this complexity will increase.
For the purpose of this review only the basic structures will be evaluated and it is
assumed that the application of this information to the more complex structures will be
similar.
The principle methods of predicting the metabolites utilises two sources of information;
- the WWW and especially the site of the University of Minnesota
- CATABOL and other published QSARs for biodegradation that predict metabolites
To assess the potential for increased concern with metabolites over their parent
compounds, either EPIsuite (US EPA 2009) or the OECD Tool Box (v1.1
http://www.oecd.org/document/54/0,3343,en_2649_34379_42923638_1_1_1_1,00.html#
Download_qsar_application_toolbox) or specific QSAR models e.g. OASIS, were used.
In all cases the approach was based on a comparison with the parent compound. It is
assumed that if the metabolite was less toxic, or more degradable than the parent
compound, then the risk assessments of petroleum substances being undertaken by
CONCAWE will be sufficiently protective of any metabolites that could be formed.
Similarly, for a PBT assessment, the metabolites were firstly compared to the parent
molecule and only for those parent molecules that may have a potential PBT concern
were the metabolites further assessed for their specific PBT properties. The models and
the basic approach are further outlined in the section below. Individual sections address
each of the principle classes of hydrocarbons.
1. Models and assessments
1.1 Prediction of the metabolites
For the purposes of this paper two sources of information were used. The first source
was the World Wide Web and especially the site of the University of Minnesota (Ellis et
al. 2006), at http://umbbd.msi.umn.edu/. This site contains information on over 900
compounds, over 600 enzymes, nearly 1000 reactions and about 350 microorganism
entries. There is a Pathway Prediction System (PPS) which is an open system for
predicting microbial catabolism of organic compounds. Graphical display of PPS rules, a
stand-alone version of the PPS and guidance for PPS users are also being developed.
These references and others have been used to describe the general mechanisms by which
hydrocarbons are degraded and hence the typical metabolites formed.
The second source of information was the model CATABOL (Jaworska et al. 2002,
supplied by the Laboratory of Mathematical Chemistry, Bourgas, http://oasis-lmc.org/).
CATABOL is a degradation simulator, which includes a library of hierarchically ordered
individual transformations (abiotic and enzymatic reactions) and a matching substructure
engine providing their subsequent performance. The catabolic steps are derived from a
set of most plausible metabolic pathways, predicted by experts for each chemical from
the training set. The MITI-I database is used for that purpose, and provides the largest
structural diversity and most consistent biodegradability assessments (O 2 yield during
OECD 301 C test) among existing data collections. Subsequently, the transformation
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