Registration Dossier

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

Additional information

The acute toxicity to daphnia and the toxicity to green algae were estimated using the current version of EPIWIN, which is considered to be a standard industry QSAR, developed by Syracuse Research Corporation for regulatory bodies in the USA. The data are considered to be reliable as the test material falls within the applicability domain of the model.

 The structure-activity relationships (SARs) presented in this program are used to predict the aquatic toxicity of chemicals based on their similarity of structure to chemicals for which the aquatic toxicity has been previously measured. Most SAR calculations in the ECOSAR Class Program are based upon the octanol/water partition coefficient (Kow).

 The ECOSAR Class program was developed primarily for the evaluation of neutral organic compounds and organic classes with excessive toxicity. Several ‘Special Classes’ are programmed into ECOSAR and do not use the log Kow value for the predictions or cannot be adequately classified from the SMILES notation alone. These ‘Special Classes’ currently include surfactants and dyes.

 QSARS are available for various anionic, cationic, non-ionic and amphoteric surfactants and two classes of cationic dyes. Instead of the log Kow values, these QSARS utilise such features as the number of ethoxylate units or the average length of a carbon chain.

 

The toxicity of the test material was estimated using the Neutral Organic class. This was considered the most appropriate model to use for the calculation based on the following reasoning:

- The Aliphatic Amines class, which is selected by ECOSAR based on structural inputs, does not accurately represent the molecule because it is an aromatic structure. Aromatic as opposed to aliphatic amines are known to have very different properties, and it is not considered scientifically justified to put them in the same class for aquatic toxicity.

- The Nonionic Surfactant special class, which was considered as a potential alternative model, does not take into account the full structure of the molecule and again does not differentiate aromatic as opposed to aliphatic structures; the only inputs are carbon chain length and the number of ethoxylates (EO).

 

The ECOSAR model v.1.11 (EPISuite v.4.10) estimated the 48 hour LC50 value for the test material to daphnia to be 78.695 mg/L.

The ECOSAR model v.1.11 (EPISuite v.4.10) estimated the 96 hour EC50 value for the test material to green algae to be 73.149 mg/L.