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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

Administrative data

Key value for chemical safety assessment

Effects on fertility

Effect on fertility: via oral route
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
NOAEL
1 000 mg/kg bw/day
Species:
rat
Effect on fertility: via inhalation route
Endpoint conclusion:
no study available
Effect on fertility: via dermal route
Endpoint conclusion:
no study available
Additional information

There are no repeated dose toxicity data on trimethoxy(2-methylpropyl)silane or its hydrolysis product, (2-methylpropyl)silanetriol, so good quality data for the related substance triethoxyisobutylsilane (CAS 17980-47-1) have been used to assess the reproductive toxicity of trimethoxy(2-methylpropyl)silane. (Isobutyl and 2-methylpropyl are synonyms).

Methanol

Information about the effects of methanol on fertility is limited. Slight increases in sperm abnormalities were noted in a study in mice (1000 mg/kg/day) although the effect on fertility was not investigated. In a rat 2-generation study there were no effects on fertility. In a cynomolgus monkey study no effects on were noted. Where effects are noted they occur only at high doses.

Ethanol

Ethanol is reported to have an effect on male fertility in some rat studies but not others and where noted generally involve sperm parameters. However, where effects are noted they occur only at high doses.

Further details on read-across are given in Section 7.5.

Neither methanol nor ethanol will contribute reproductive effects at the dose levels tested.


Short description of key information:
There are no repeated dose toxicity data on trimethoxy(2-methylpropyl)silane or its hydrolysis product, (2-methylpropyl)silanetriol, so good quality data for the related substance triethoxyisobutylsilane (CAS 17980-47-1) have been used to assess the reproductive toxicity of trimethoxy(2-methylpropyl)silane.

In a rat oral one-generation reproductive toxicity study conducted to OECD 415 and to GLP (Safepharm Laboratories Ltd., 1992b) the NOAEL for parental general toxicity and for reproductive toxicity for triethoxyisobutylsilane was at least 1000 mg/kg bw/day, as no adverse effects were observed at any dose.

Justification for selection of Effect on fertility via oral route:
The selected study is the only reproductive toxicity study available for a relevant surrogate substance. It was conducted in accordance with an appropriate OECD test guideline and in compliance with GLP.

Effects on developmental toxicity

Description of key information
There are no repeated dose toxicity data on trimethoxy(2-methylpropyl)silane or its hydrolysis product, (2-methylpropyl)silanetriol, so good quality data for the related substance triethoxyisobutylsilane (CAS 17980-47-1) have been used to assess the developmental toxicity of trimethoxy(2-methylpropyl)silane.
In an oral developmental toxicity study conducted to OECD 414 and to GLP (Safepharm Laboratories Ltd., 1991) there were no effects on rat foetal development and the NOAEL was therefore at least 1000 mg/kg bw/day (the highest dose tested). 
In addition to the key developmental study, no adverse effects on the landmarks of offspring development or on the offspring response to simple reflexological tests were observed in a one-generation reproductive toxicity study (Safepharm Laboratories Ltd., 1992b).
Effect on developmental toxicity: via oral route
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
NOAEL
1 000 mg/kg bw/day
Species:
rat
Effect on developmental toxicity: via inhalation route
Endpoint conclusion:
no study available
Effect on developmental toxicity: via dermal route
Endpoint conclusion:
no study available
Additional information

There are no repeated dose toxicity data on trimethoxy(2-methylpropyl)silane or its hydrolysis product, (2-methylpropyl)silanetriol, so good quality data for the related substance triethoxyisobutylsilane (CAS 17980-47-1) have been used to assess the developmental toxicity of trimethoxy(2-methylpropyl)silane. (Isobutyl and 2-methylpropyl are synonyms).

Further details on read-across are given in Section 7.5.

Neither methanol nor ethanol will contribute developmental effects at the dose levels tested.


Justification for selection of Effect on developmental toxicity: via oral route:
The selected study is the only developmental toxicity study available for a relevant surrogate substance. It was conducted in accordance with an appropriate OECD test guideline and in compliance with GLP.

Justification for classification or non-classification

Based on the available read-across oral reproductive and developmental toxicity studies, trimethoxy(2 -methylpropyl)silane is not classified for effects on fertility or development according to Regulation 1272/2008/EC.

Additional information