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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

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Classification & Labelling & PBT assessment

PBT assessment

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Administrative data

PBT assessment: overall result

1112-39-6 Dimethoxydimethylsilane
Type of composition:
boundary composition of the substance
State / form:
Reference substance:
1112-39-6 Dimethoxydimethylsilane
PBT status:
the substance is not PBT / vPvB

The PBT Assessment is based on the criteria set out in the “Guidance on information requirements and chemical safety assessment, Chapter R.11: PBT Assessment” (ECHA, 2017).

Dimethylsilanediol (CAS No. 1066-42-8) is the silanol hydrolysis product of the registered substance dimethoxy(dimethyl)silane (CAS No. 1112-39-6).


Persistence (P) assessment

Based on the collective evidence from higher tier biodegradation studies, dimethylsilanediol does not show any signs of a significant biodegradation under environmentally relevant conditions in various media such as soil and sediment. Therefore, dimethylsilanediol does meet the screening criteria for persistence in the environment (P/vP) based on.


Bioaccumulation (B) assessment

Dimethylsilanediol has a predicted log Kow of – 0.38 (QSAR) and therefore does not meet the screening criteria for bioaccumulation (log Kow < 3, not B/vB).


Toxicity (T) assessment

The substance does not show any acute or chronic aquatic effects. However, it is classified as toxic for reproduction category 1B according to Regulation EC No 1272/2008. Therefore, the criteria for “T” based on mammalian effects are met and dimethylsilanediol meets the screening criteria for T.


In conclusion, dimethylsilanediol does not meet the overall criteria for PBT or vPvB, based on ECHA guidance R.11 (2017).