Registration Dossier

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

Additional information

Within the ‘red disazo condensation pigments’ acute aquatic toxicity data on all three trophic levels are available. This includes two studies for acute toxicity on zebrafish Danio rerio (CAS 68516-75-6 and CAS 71566-54-6), two studies on immobilization of the waterflea Daphnia magna (CAS 40618-31-3 and CAS 52238-92-3) and studies of toxicity on the green algae Desmodesmus subspicatus and Pseudokirchneriella supcapitata (CAS 68516-75-6 and CAS 71566-54-6). Furthermore for one ‘red disazo condensation pigment’ long-term data on reproduction of the waterflea Daphnia magna are available (CAS 71566-54-6).

Disazo condensation red pigments are all of low solubility in water and in octanol. They do not contain functional groups that are susceptible to pH dependent hydrolysis at environmentally relevant pH. The pigments are generally not readily biodegradable and additionally adsorption to the solid soil phase is not expected. Due to the low logPow and the high molecular weight of all pigments, bioaccumulation is not expected. Their relative density is between 1.4 and 1.61 and all decompose before melting at temperatures above 300°C. Since the molecular structure and the physico-chemical properties of the ‘red disazo condensation pigments’ are very similar, the available studies are sufficient to cover the aquatic toxicity endpoints. Furthermore, studies on aquatic toxicity are available for the most water soluble pigment (CAS 71566-54-6) and the pigment with the highest logPow and highest octanol solubility (CAS 68516-75-6) to cover the complete range. Therefore, this read across approach is in accordance with Regulation (EC) No 1907/2006, Annex XI, 1.5. Grouping of substance and read across approach as it is explained within the analogue justification in the Annex.

After exposure to ‘red disazo condensation pigments’, no effects on aquatic organisms occurred within the range of water solubility, neither in acute nor in chronic studies. These results confirm the expectation, that ‘red disazo condensation pigments’ are considered to be essentially not bioavailable, due to the large molecular size together with the negligible low solubility.