Enhanced ready biodegradability screening tests for the evaluation of potential PBT substances.

In persistence assessment enhanced ready biodegradation tests (eRBT) are aimed to close the gap between screening tests and complex simulation tests. However, only few data from these tests are available and neither guidance on the design and interpretation of eRBTs, nor suitable validity criteria have been established so far. In a practical testing programme 5 compounds with controversial degradation data have been tested in 4 test series including prolongation to 60 days and use of different inocula (activated sludge, final effluent from a STP), flask sizes, and endpoints (CO, O, DOC).