B-compass Fish

In environmental risk assessment, the fish bioconcentration factor (BCF) has been established as an assessment criterion for estimating the bioaccumulation potential of chemicals. The prediction of BCFs using suitable models is becoming more and more accepted as an alternative higher tier BCF assessment in replacement to animal testing. An important aspect in the prediction models is consideration of biotransformation.

In B-compass fish, biotransformation data from in vitro assays with cells or S9 fraction can be used for BCF prediction. For doing so, the in vitro biotransformation data inserted by the user are automatically extrapolated to the corresponding in vivo rates (in vitro-in vivo extrapolation) and then used in the BCF prediction model. B-compass fish allows not only hepatic biotransformation to be considered but also extrahepatic biotransformation in gill and gastro-intestinal tract (GIT) can be represented.

Conceptually, two models of different complexity are implemented in B-compass fish: a simple model and a more complex model. The more complex model considers blood flow limitation as well as the potential first-pass effect in the gills following chemical uptake via ventilation and the sequential order of GIT and liver biotransformation while the simple model neglects these specific features (for more details please refer to our corresponding paper). The results of both models are provided simultaneously without any additional efforts for the user.

Besides in vitro biotransformation data, information on the modelled fish and information on the partition properties of the chemical of interest are required as input. The partition information can either be provided in form of the octanol-water partition coefficient of the chemical or in form of descriptors for poly-parameter free energy relationships (ppLFERs; the required descriptors can be requested from the LSER database). Accordingly, there are two versions of B-compass fish that can be downloaded here, both of which differ only in the partition parameters that are required as input data.

Please cite as

Krause, S. and K.-U. Goss, B-compass Fish Version 1.2 (ppLFER approach), Leipzig, Germany, Helmholtz Centre for Environmental Research, 2021

please cite as

Krause, S. and K.-U. Goss, B-compass Fish Version 1.2 (Kow approach), Leipzig, Germany, Helmholtz Centre for Environmental Research, 2021

Krause, S. and K.-U. Goss, 2020, Comparison of a simple and a complex model for BCF prediction using in vitro biotransformation data. Chemosphere. 256: p. 127048