Expert system for PBT profiling

The system assesses the PBT profile of chemicals, taking into account the metabolic transformations of the parent chemicals. CATALOGIC is used to assess the persistence of chemicals on the basis of the predicted BOD values. Presently the system simulates the biodegradability in OECD 301C (MITI-I), OECD 301F (kinetic biodegradation model). The persistent parent chemicals and their stable metabolites are further submitted to evaluation of their bioaccumulation and toxicity. The evaluation of bioaccumulation potential in fish is based on the base-line concept for defining BCF. Firstly the value of maximum bioaccumulation is obtained, passive diffusion (assessed by a logKow-based model) being the only driving force. Subsequently, mitigating factors such as molecular size and flexibility, ionization and metabolism are taken into account. Bioaccumulation is only evaluated for amounts of parent chemicals or their metabolites exceeding a user defined threshold. A library of QSAR models for acute and chronic toxic endpoints is used to characterize the toxic profile of chemicals and their metabolites.




Environmental fate and ecotoxicity models