Environmental Quality Standards (EQS) or Predicted No-Effect Concentrations (PNEC) are sometimes available from different EU Member States or chemical regulations (e.g. PPP, BPD or REACH). The Lowest PNEC shown here are agreed by NORMAN experts to be used preliminary for prioritisation purposes. If the measured environmental concentrations (MEC) in the NDS exceed a Lowest PNEC which is not robust, a review is required to determine whether a regulatory concern exists. The lowest PNECs are preferably based on experimental eco-toxicity data, but in case of no or insufficient empirical endpoints, QSAR predictions were used to estimate a provisional P-PNEC value to allow for a first screening.

Most of the Lowest PNECs were derived for freshwater. Unless there is an experimental value for other matrices, the following calculations were used for derivation of the Lowest PNECs in:


All of the above mentioned PNECs refer to long-term exposure. A short overview on the methodology to derive the different PNECs can be downloaded here.



Norman SusDat IDSubstanceCAS No.Lowest PNECfw [µg//l]Lowest PNECmarine [µg//l]Lowest PNECsed_fw [µg//kg dw]Lowest PNECsed_marine [µg//kg dw]Lowest PNECbio_fw [µg//kg ww]Lowest PNECbio_marine [µg//kg ww]