Registration Dossier

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

Additional information

The registered substance is susceptible to hydrolysis reactions, as described in Section 5.1.2 of IUCLID. Therefore it is likely that, in the available aquatic studies, the test organisms were exposed to a mixture of the hydrolysis products of the substance and the test substance.

A functional group associated with ecotoxicity by a specific mode of action (thiocyanate) is present in both the registration substance and the silanol hydrolysis product, and the effects seen are attributed to this. It is therefore reasonable to conclude that both the parent and hydrolysis product could contribute to any effects observed.

Reliable short-term toxicity tests results are available for freshwater fish (Danio rerio, tested as Brachydanio rerio), invertebrates (Daphnia magna) and algae (Desmodesmus subspicatus, tested as Scenedesmus subspicatus). The relevant short-term values are:

Fish: LC50 (96 h): between 10 and 18 mg/l (nominal); expressed in terms of parent.

Invertebrate: EC50 (24 h): 29 mg/l (nominal), expressed in terms of parent.

Algae: ErC50 (96 h): 160 mg/l; NOEC: 32 mg/l (nominal) expressed in terms of parent.

Reliable long-term toxicity test results are not available. A test proposal is in place for long-term toxicity to aquatic invertebrates. The need for long-term toxicity to fish data is waived and will be reviewed once the long-term toxicity to invertebrates study results are available.

An activated sludge respiration inhibition 3 hour EC50 value of 130 mg/l and an EC10 value of 4.2 mg/l (loading rate, nominal) were determined in a reliable study. It was not possible to determine a NOEC value in the study (NOEC was <1.0 mg/l (loading rate, nominal)).