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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

Endpoint summary

Administrative data

Description of key information

Additional information

There are no reliable aquatic toxicity data available for methylsilanetriyl triacetate (CAS 4253-34-3), therefore good quality data for the structurally-related substances, triethoxy(methyl)silane (CAS 2031-67-6) and trimethoxy(methyl)silane (CAS 1185-55-3), have been read across. The data with triethoxy(methyl)silane have been chosen as key.

 

Reliable short-term toxicity tests results are available for freshwater fish (Danio rerio), invertebrates (Daphnia magna) and algae (Pseudokirchnieriella subcapitata) for triethoxy(methyl)silane (CAS 2031-67-6). The relevant short-term values are:

Fish: LC50 (96 h): >500 mg/l nominal concentration or >213.7 mg/l expressed in terms of concentration of the hydrolysis product, methylsilanetriol.

Daphnia: EC50 (48 h): >500 mg/l nominal concentration or >213.7 mg/l expressed in terms of concentration of the hydrolysis product, methylsilanetriol.

Algae: EC50 (72 h): >500 mg/l; NOEC: =500 mg/l nominal concentration or >213.7 mg/l and =213.7 mg/l, respectively, expressed in terms of concentration of the hydrolysis product, methylsilanetriol.

Reliable data for long-term toxicity to Daphnia magna are available for the read-across substance, trichloro(ethyl)silane (CAS 115-21-9). In this test the 21-day NOEC for survival and reproduction was found to be =100 mg/l, nominal concentration.  The test substance very rapidly hydrolyses to ethylsilanetriol and hydrochloric acid. The NOEC expressed in terms of the silanol hydrolysis product, ethylsilanetriol, is =66 mg/l.

 

An activated sludge respiration inhibition 3 hour EC10 value of >100 mg/l expressed in terms of trimethoxy(methyl)silane and >69 mg/L when expressed as the silanol hydrolysis product, methylsilanetriol (nominal) were determined in a reliable study.

 

The rapid hydrolysis of triethoxy(methyl)silane (CAS 2031-67-6 ) (half-life 5.5 h at pH 7 and 20-25 °C) means it is likely that the test organisms in each test were exposed primarily to the hydrolysis products, methylsilanetriol and ethanol. 

 

Refer to IUCLID Section 6 endpoint summary (CSR Section 7.0) for further discussion of the approach to chemical safety assessment and justification for read across.