Registration Dossier

Data platform availability banner - registered substances factsheets

Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

No chronic toxicity toward invertebrates, plants and microorganisms was observed up to the highest tested concentrations.

Additional information

Dimethoxy(dimethyl)silane (CAS No. 1112-39-6) hydrolyses rapidly in contact with water (DT50 < 0.6 h), to the silanol hydrolysis product dimethylsilanediol (DMSD, CAS No. 1066-42-8) and the alcohol hydrolysis product methanol (CAS No. 67-56-1). The ECHA guidance R.16 states that “for substances where hydrolytic DT50 is less than 12 h, environmental effects are likely to be attributed to the hydrolysis product rather than to the parent itself” (ECHA, 2016). The ECHA guidance R.16 also suggests that in case the hydrolysis half-life is less than 12 h, the breakdown products, rather than the parent substance, should be evaluated for aquatic toxicity. Methanol is well described in the public domain literature. It has a low environmental hazard profile and is therefore not considered contributory to the overall ecotoxicity of the registered substance (OECD SIDS, 2004). Thus, the hazard assessment for the terrestrial compartments is based on the silanol hydrolysis product dimethylsilanediol (DMSD, CAS No. 1066-42-8).


DMSD is highly water soluble (1.0 E+06 mg/L) and has a low potential for sorption to organic matter in soil and sediment (Koc = 0.19 to 1.2).
For aquatic toxicity, no hazard was identified based on the acute and chronic tests available for all three trophic levels, showing no effects up to the highest tested concentrations. Since the substance is well soluble, increased toxicity in other long-term tests is unlikely.
For terrestrial toxicity, experimental studies for the chronic toxicity are available for invertebrates, terrestrial plants and soil microorganisms. In all studies, no statistically significant adverse effects were recorded up to the highest tested concentrations.


OECD SIDS, 2004. Methanol - SIDS Initial Assessment Report For SIAM 19, Berlin, Germany: UNEP Publications.