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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Ecotoxicological information

Sediment toxicity

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Administrative data

Link to relevant study record(s)

Reference
Endpoint:
sediment toxicity: long-term
Data waiving:
other justification
Justification for data waiving:
other:
Justification for type of information:
For detailed information on this adaptation based on Annex XI (Section 3), please refer to the CSR attached in Section 13.

Description of key information

The substance hydrolyses rapidly and its silanol hydrolysis product has a log Kow< 3. Therefore, partitioning to the sediment compartment is expected to be minimal. Furthermore, in accordance with Annex XI, Section 3, exposure of aquatic organisms to diphenylsilanediol was assessed as not significant (RCR << 1). Additionally, long-term sediment toxicity studies are not required for Annex IX substances under the REACH Regulation.

Key value for chemical safety assessment

Additional information

In accordance with Annex XI, Section 3, exposure of aquatic organisms to diphenylsilanediol is not significant. Furthermore, the hazard assessment based on acute aquatic toxicity data shows moderate toxicity toward aquatic organisms among all three trophic levels (lowest acute effect in algae, ErC50 (72 h) = 9 mg/L). The substance is well soluble and thus, greater toxicity in long-term tests is unlikely.

PNECs were derived for the aquatic compartment by use of the lowest EC50 value observed in the toxicity study on algae. As the substance hydrolyses rapidly, the environmental hazard assessment, PNEC derivation and risk characterization is based on the silanol hydrolysis product following a worst case approach. The other hydrolysis product, hydrochloric acid, readily dissociates in water into hydrated protons and chloride anions. Thus, it is ionised and neutralisation depends on the buffer capacity of the receiving water. Toxicity only occurs when the buffering capacity of the receiving water is exceeded and pH values fall below pH 6. The pH in rivers and lakes fluctuates within a natural range. The natural pH range in aquatic systems is generally not expected to be perturbed to a relevant extent by anthropogenic emissions when appropriate risk control measures are in place. Variations in effect values of experimental studies can largely be explained by variations in the buffer capacity of the test media (OECD, 2002). The risk characterization for the silanol hydrolysis product indicated no risk to the aquatic environment (RCR < < 1).

For detailed information on the risk assessment please see the attached documentation.