Hexamethylenediamine

Endpoint summary

Additional information

Acute data of various reliability, produced from international guidelines, are available for the three trophic levels (Algae, Invertebrates and Fish). In aqueous solution, the pH of the substance is naturally high and requires pH-adjustment for testing under environmentally realistic conditions. Several studies did not take account of this difficulty and as a result several endpoint values have been found to be inconsistent. An algae study including chemical analysis was performed according to GLP and confirmed the stability of the test substance during aquatic tests. It is considered that the algae study was carried out under more stringent conditions (presence of high light intensity, static conditions over 72 h, at a higher temperature and in the presence of algal cells) and therefore high stability during other aquatic tests can be expected. The lowest acute EC50 is 31.5 mg/L, based on the geometric mean of two 48h-EC50 daphnid tests while reliable tests performed on fish and algae give L(E)C50 superior to 100 mg/L. Chronic data of good reliability from international guidelines are also available for Algae and Invertebrates. The lowest value is a NOEC of 4.2 mg/L based on a 21 d reproduction test on daphnids performed according to the OECD 211 Guideline. A chronic fish study has been waived due to the much lower sensitivity of this trophic level compared to the daphnid data.

In an activated sludge respiration inhibition test according to OECD 209 nitrification proved to be the most sensitive endpoint (highest test item concentration: 1000 mg/L), with an: EC50 (3h; nitrification) of 291 mg/L.