Registration Dossier

Diss Factsheets

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

Additional information

There are numerous ecotoxicity studies conducted on PPD in the last 30 years, however in most cases the concentrations of PPD in the test vessels were not well maintained and the test designs were not appropriate. PPD is now known to degrade rapidly, i.e., oxidise quickly in presence of oxygen and light (half life of about 5 to 8 hours, CSR Section 4.1.3) to produce new reaction products. Some of these new reaction products have been identified (mainly dimers, trimers and Bandrowski’s base).  

For this reason new aquatic toxicity studies with improved test designs and analytical methods have been conducted and are being considered. The aim of these studies was to maintain the concentrations of PPD as close as possible to nominal concentrations to reflect the ecotoxicity of the substance. The newly generated data have impacted the overall endpoint assessment and consequential derivation of PNECs. Furthermore, initiatives have been taken to run ecotoxicity testing with known degradation products of PPD. An acute toxicity test with the Bandrowski's base has in the meanwhile been conducted but no final report is yet available. From the preliminary data from this fish embryo acute toxicity test, a LC50 of 3.478 -6.303 mg/L (nominal) was calculated, the range depending on the concentration and age of stock solutions used. The dossier will be updated when the final report from this study is ready or when other new data are available.

Categories Display