Registration Dossier
Registration Dossier
Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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.
Use of this information is subject to copyright laws and may require the permission of the owner of the information, as described in the ECHA Legal Notice.
EC number: 229-929-1 | CAS number: 6843-66-9
Toxicity to aquatic algae and cyanobacteria
Administrative data
Link to relevant study record(s)
Description of key information
EC50 (72 h) = 9 mg/L and NOEC = 1.1 mg/L (meas. arithm. mean, OECD 201) based on read across to the hydrolysis product CAS 947-42-2
Key value for chemical safety assessment
- EC50 for freshwater algae:
- 9 mg/L
- EC10 or NOEC for freshwater algae:
- 1.1 mg/L
Additional information
No data concerning toxicity to algae are available for the target substance Dimethoxydiphenylsilane (CAS 6843 -66 -9). Due to the rapid rate of hydrolysis of the substance (0.6 h at 20 -25°C and pH 7), it was considered appropriate to use measured data of its hydrolysis product Diphenylsilanediol (CAS 947-42-2) to determine the toxicity of the substance to algae.
A study (2004) is available testing the toxicity of Diphenylsilanediol (CAS 947-42-2), which is the hydrolysis product of the target substance, to algae. The test was conducted according to OECD 201 guidance and GLP standards. Pseudokirchneriella subcapitata as the test organism was exposed for 72 h to the nominal test item concentrations of 0 (control), 0.47, 0.94, 1.9, 3.8, 7.5 and 15 mg/L (mean measured: 0, 0.55, 1.1, 2.2, 4.4, 9.0 and 18 mg/L). The test item concentrations in the medium were analytically monitored via HPLC method. The recoveries were > 80% of the nominal values. Biological effects by the substance on algae were observed resulting in an ErC50 (72 h) of 9 mg/L and a NOErC (72 h) of 1.1 mg/L (both mean measured). This study is considered reliable and was selected as key.
Additional supporting information was withdrawn from a study on the toxicity of the related substance Cyclohexyldimethoxymethylsilane (CAS 17865-32-6) to algae. The test was conducted according to the OECD guidance 201 and GLP standards. Desmodesmus subspicatus was exposed for 72 h to the nominal test item concentrations of 0 (control), 6.25, 12.5, 25, 50 and 100 mg/L. The study resulted in an ErC50 (72 h) of 35 mg/L and a NOErC (72 h) of 12.5 mg/L (both nominal).
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.
Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.
