Registration Dossier

Ecotoxicological information

Toxicity to terrestrial arthropods

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

Toxicity to terrestrial arthropods: LC50 (28-day): 813 mg/kg dry weight for effects on mortality in Folsomia candida, measured, read-across from an analogous substance, decamethylcyclopentasiloxane (D5, CAS 541-02-6) within the Reconsile Siloxanes Category.

Toxicity to terrestrial arthropods: IC50(28-day): 767 mg/kg dry weight for effects on reproduction in Folsomia candida, measured, read-across from an analogous substance, decamethylcyclopentasiloxane (D5, CAS 541-02-6) within the Reconsile Siloxanes Category.

Toxicity to terrestrial arthropods: NOEC (28-day): 377 mg/kg dry weight for effects on mortality and reproduction in Folsomia candida, measured, read-across from an analogous substance, decamethylcyclopentasiloxane (D5, CAS 541-02-6) within the Reconsile Siloxanes Category.

Key value for chemical safety assessment

Long-term EC10, LC10 or NOEC for soil dwelling arthropods:
377 mg/kg soil dw

Additional information

There are no data describing the long-term toxicity of the registered substance to terrestrial arthropods. However, data are available for the siloxane decamethylcyclopentasiloxane (D5, CAS: 541 -02 -6). A 28-day LC50value of 813 mg/kg dry weight and a 28 day IC50value of 767 mg/kg dry weight have been determined for the effects of the test substance on mortality and reproduction of Folsomia candida. A NOEC of 377 mg/kg dry weight has been determined by the reviewer on the basis of a visual examination of the data for both mortality and reproduction.

This data will be considered in the derivation of the PNECsoilof the registered substance.

An OECD TG 222 earthworm reproduction study has already been proposed for a structurally-similar substance within the Siloxanes Category, Silsesquioxanes, Phenyl (CAS 70131-69-0). The approach to chemical safety assessment for octaphenylcyclotetrasiloxane will be reconsidered once further data becomes available. The earthworm is the standard organism for soil macroorganisms and there is no indication that arthropods would be any more susceptible.

Read-across of the terrestrial toxicity data for D5 to octaphenylcyclotetrasiloxane is considered to be suitable as an interim approach for the purpose of chemical safety assessment.

Refer to Section 6.3 for further discussion.