Registration Dossier
Registration Dossier
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EC number: 242-272-5 | CAS number: 18395-30-7
Ecotoxicological Summary
Administrative data
Hazard for aquatic organisms
Freshwater
- Hazard assessment conclusion:
- PNEC aqua (freshwater)
- PNEC value:
- 0.82 mg/L
- Assessment factor:
- 500
- Extrapolation method:
- assessment factor
- PNEC freshwater (intermittent releases):
- 8.2 mg/L
Marine water
- Hazard assessment conclusion:
- PNEC aqua (marine water)
- PNEC value:
- 0.082 mg/L
- Assessment factor:
- 5 000
- Extrapolation method:
- assessment factor
STP
- Hazard assessment conclusion:
- PNEC STP
- PNEC value:
- 100 mg/L
- Assessment factor:
- 10
- Extrapolation method:
- assessment factor
Sediment (freshwater)
- Hazard assessment conclusion:
- PNEC sediment (freshwater)
- PNEC value:
- 3.2 mg/kg sediment dw
- Extrapolation method:
- equilibrium partitioning method
Sediment (marine water)
- Hazard assessment conclusion:
- PNEC sediment (marine water)
- PNEC value:
- 0.32 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:
- 0.16 mg/kg soil dw
- Extrapolation method:
- equilibrium partitioning method
Hazard for predators
Secondary poisoning
- Hazard assessment conclusion:
- no potential for bioaccumulation
Additional information
Trimethoxy(2-methylpropyl)silane hydrolyses rapidly in contact with water or atmospheric moisture (estimated 4.1 h at pH 7 and 25°C), to produce (2-methylpropyl)silanetriol and methanol. At the concentrations relevant to the assessmentmethanol is understood to be non hazardous to aquatic organisms, further considerations are given below. REACH guidance (ECHA 2010A, R.16) states that “for substances where hydrolytic DT50 is less than 12 hours, environmental effects are likely to be attributed to the hydrolysis product rather than to the parent itself”. TGD and REACH guidance (EC 2003) and R.16 (2010A) also suggest that when the hydrolysis half-life is less than 12 hours, the breakdown products, rather than the parent substance, should be evaluated for aquatic toxicity.Therefore, the environmental hazard assessment (aquatic, sediment and soil) is based on the properties of the silanol hydrolysis product, (2-methylpropyl)silanetriol, in accordance with REACH guidance. As described in Section 1.3, condensation reactions of the silanetriol are possible.
Conclusion on classification
Trimethoxy(2-methylpropyl)silanehydrolyses rapidly and the silanol hydrolysis product is not readily biodegradable.
Trimethoxy(2-methylpropyl)silaneis not classified for the environment in the EU according to Regulation (EC) No 1272/2008 because data available for the substance indicate that it is not toxic up to a concentration of 100 mg/l, i.e. lowest E(L)C50 is >100 mg/l.Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.
Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.
