Registration Dossier

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

Additional information

Based on the analytical problems observed in the experimental ecotoxicological studies, a weight of evidence approach with QSAR estimations has been considered more appropriate to assess the aquatic toxicity of the substance than basing the results uniquely upon the exisiting aquatic dataset. Further investigation is ongoing on this difficult substance in order to determine whether instability or analytical issues accounted for the loss observed in older test samples.

To obtain reliable endpoint values, geometric means between the experimental results (based on initial measured concentrations) and the QSAR estimations (ECOSAR v1.11 QSAR model available from the U.S. EPA) were determined for three trophic levels: Algae, Invertebrates and Fish. The results are summarised in the table below.

Organism

EC50/LC50

NOEC

Flag / reliability

Reference in IUCLID / comments

Acute

Aquatic algae

Not relevant

3.39 mg/L

2.10 mg/L

Not relevant

Weight of evidence approach

Aquatic invertebrates

Not relevant

4.65 mg/L

-

Not relevant

Weight of evidence approach

Fish

Not relevant

1.87 mg/L

-

Not relevant

Weight of evidence approach

Micro-organisms

activated sewage sludge

30min: 12400 mg/L

-

K/2

Toxicity to microorganisms, Caspers, 1996, RS, K

Among all data available, fish seems to be the most sensitive species in acute exposure with an estimated 96h-LC50 at 1.87 mg/L. 

No valid chronic studies are available. The choice to perform long-term studies will be defined after further investigation on this difficult substance.