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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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: 211-656-4 | CAS number: 681-84-5
Toxicity to microorganisms
Administrative data
Link to relevant study record(s)
Description of key information
Toxicity to microorganisms: 3hr EC50 >100 mg/l (activated sludge respiration inhibition, OECD 209), read-across from an analogue substance.
Key value for chemical safety assessment
Additional information
There are no reliable microorganism toxicity data available for tetramethyl orthosilicate, therefore good quality data for the analogue substance, tetraethyl orthosilicate (CAS 78 -10 -4), have been read across. Both substances share the same hydrolysis product, silicic acid
; the other hydrolysis products being methanol and ethanol, respectively. Methanol and ethanol do not have adverse effects on microorganisms.Both tetramethyl orthosilicate and tetraethyl orthosilicate are within an analogue group of substances that exhibit no evidence of significant toxicity to microorganisms
It is therefore considered valid to read-across the results for tetraethyl orthosilicate to fill the data gap for the registered substance.Additional information is given in a supporting report (PFA, 2013j) attached in Section 13 of the IUCLID 5 dossier.
A 3hr EC50value of >100 mg/l (nominal) was determined for tetraethyl orthosilicate.
The study is considered to be reliability 1 (reliable without restrictions); the read across of the result is considered to be reliability 2 (reliable with restrictions).
The hydrolysis rate for tetraethyl orthosilicate is 4.4 hours at pH7 and 25°C, and so it would be hydrolysed to a lesser extent than tetramethyl orthosilicate in the timescale of the test. Therefore, microorganisms toxicity data for Silicic acid (H4SiO4), tetraethyl ester, hydrolyzed (CAS 68412-37-3), which is a member of the same analogue group, has been used as supporting data for the read-across. Microorganism toxicity data from a non-standard oxygen consumption study with Pseudomonas putida is available for Silicic acid (H4SiO4), tetraethyl ester, hydrolyzed. The test procedure was in accordance with generally accepted scientific standards and described in sufficient detail and in compliance with GLP, with acceptable restrictions. The restrictions were that a reference substance was not used to check the sensitivity of the microorganisms, and an emulsifier was used which could have affected the results.
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.
