Registration Dossier

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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:
PNEC aqua (freshwater)
PNEC value:
1 mg/L
Assessment factor:
500
Extrapolation method:
assessment factor
PNEC freshwater (intermittent releases):
10 mg/L

Marine water

Hazard assessment conclusion:
PNEC aqua (marine water)
PNEC value:
0.1 mg/L
Assessment factor:
10 000
Extrapolation method:
assessment factor
PNEC marine water (intermittent releases):
5 mg/L

STP

Hazard assessment conclusion:
PNEC STP
PNEC value:
10 mg/L
Assessment factor:
10
Extrapolation method:
assessment factor

Sediment (freshwater)

Hazard assessment conclusion:
PNEC sediment (freshwater)
PNEC value:
3.659 mg/kg sediment dw
Extrapolation method:
equilibrium partitioning method

Sediment (marine water)

Hazard assessment conclusion:
PNEC sediment (marine water)
PNEC value:
0.366 mg/kg sediment dw
Extrapolation method:
equilibrium partitioning method

Hazard for air

Air

Hazard assessment conclusion:
no hazard identified

Hazard for terrestrial organisms

Soil

Hazard assessment conclusion:
PNEC soil
PNEC value:
0.145 mg/kg soil dw
Extrapolation method:
equilibrium partitioning method

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:
no potential for bioaccumulation

Additional information

Conclusion on classification

Classification related data

Hydrolysis

Diethoxy(methyl)silane (CAS 2031-62-1): hydrolysis half-life2 min at 25 °C and pH7 (EU Method C.7)

 

Biodegradation

Not readily biodegradable: 0% (inorganic C-analysis) in 28 d (OECD 310) based on read-across from CAS 1066-40-6

 

Bioaccumulation

Diethoxy(methyl)silane (parent): Log Kow = 1.7 (QSAR)

Methylsilanediol (hydrolysis product): Log Kow = -1.0 (QSAR)

Methylsilanetriol (hydrolysis product): Log Kow = -2.4(QSAR)

Ethanol (hydrolysis product): Log Kow = - 0.3 (measured)

 

Acute toxicity

to fish: LC50 (96 h) > 500 mg/L (nominal, EU Method C.1)

to aquatic invertebrates: EC50 (48 h) > 500 mg/L (nominal, EU Method C.2)

to algae: ErC50 (72 h) > 500 mg/L (nominal, EU Method C.3)

 

Chronic toxicity

to algae: NOErC (72 h) ≥ 500 mg/L (nominal, EU Method C.3)

 

Conclusion on classification

Diethoxy(methyl)silane (CAS 2031-62-1) hydrolyses rapidly in water (estimated DT50 < 2 min at pH7 and 25 °C), to methylsilanetriol and ethanol. The silanol hydrolysis product is not readily biodegradable. Acute toxicity data from the analogue substance triethoxy(methyl)silane (CAS 2031-67-6) are available for all three trophic levels while chronic data are available for algae. No acute or chronic toxicity was recorded. On this basis, diethoxy(methyl)silane is not classified as hazardous to the environment according to the consolidated version of Regulation (EC) No 1272/2008 (CLP) and all further amendments.