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Diss Factsheets
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EC number: 242-272-5 | CAS number: 18395-30-7
- Life Cycle description
- Uses advised against
- Endpoint summary
- Appearance / physical state / colour
- Melting point / freezing point
- Boiling point
- Density
- Particle size distribution (Granulometry)
- Vapour pressure
- Partition coefficient
- Water solubility
- Solubility in organic solvents / fat solubility
- Surface tension
- Flash point
- Auto flammability
- Flammability
- Explosiveness
- Oxidising properties
- Oxidation reduction potential
- Stability in organic solvents and identity of relevant degradation products
- Storage stability and reactivity towards container material
- Stability: thermal, sunlight, metals
- pH
- Dissociation constant
- Viscosity
- Additional physico-chemical information
- Additional physico-chemical properties of nanomaterials
- Nanomaterial agglomeration / aggregation
- Nanomaterial crystalline phase
- Nanomaterial crystallite and grain size
- Nanomaterial aspect ratio / shape
- Nanomaterial specific surface area
- Nanomaterial Zeta potential
- Nanomaterial surface chemistry
- Nanomaterial dustiness
- Nanomaterial porosity
- Nanomaterial pour density
- Nanomaterial photocatalytic activity
- Nanomaterial radical formation potential
- Nanomaterial catalytic activity
- Endpoint summary
- Stability
- Biodegradation
- Bioaccumulation
- Transport and distribution
- Environmental data
- Additional information on environmental fate and behaviour
- Ecotoxicological Summary
- Aquatic toxicity
- Endpoint summary
- Short-term toxicity to fish
- Long-term toxicity to fish
- Short-term toxicity to aquatic invertebrates
- Long-term toxicity to aquatic invertebrates
- Toxicity to aquatic algae and cyanobacteria
- Toxicity to aquatic plants other than algae
- Toxicity to microorganisms
- Endocrine disrupter testing in aquatic vertebrates – in vivo
- Toxicity to other aquatic organisms
- Sediment toxicity
- Terrestrial toxicity
- Biological effects monitoring
- Biotransformation and kinetics
- Additional ecotoxological information
- Toxicological Summary
- Toxicokinetics, metabolism and distribution
- Acute Toxicity
- Irritation / corrosion
- Sensitisation
- Repeated dose toxicity
- Genetic toxicity
- Carcinogenicity
- Toxicity to reproduction
- Specific investigations
- Exposure related observations in humans
- Toxic effects on livestock and pets
- Additional toxicological data
Endpoint summary
Administrative data
Description of key information
In the key acute oral toxicity study (Hüls Prüfinstitut für Toxikologie, 1993a) conducted to OECD test guideline (now deleted 401) and GLP, the oral LD50 was greater than 2000 mg/kg bw in male and female rats. Within the first three hours after administration in males and the first six hours in females, there were signs of toxicity. Within three hours the signs were ruffled fur, crouching posture, mild sedation, ataxia, and swaying motion. By five to six hours there were no signs in 8/10 animals. Six hours after administration, one female had signs of severe toxicity (ruffled fur, medium to heavy sedation, ataxia, prone position, hypothermia, laboured breathing, closed eyes and chromodacryorrhea. While all other animals ate their food, after three hours this animal still refused to eat. After 24 hours there were no signs of toxicity in any of the animals.
In the key acute inhalation study (that was comparable to OECD 403 and to GLP (DCC, 1984), the LC50 for Dow Corning X1-2204 (isobutyltrimethoxysilane) was greater than 1525 ppm (11 mg/l) (the only concentration tested) in Sprague-Dawley rats. The animals were lethargic and unresponsive during the exposure period. However, on removal from the chamber, the animals quickly recovered and did not show any stress or signs of toxicity during the 14-day observation period.
There are no dermal data for the registration substance, but the skin irritation and skin sensitisation studies did not report any systemic effects. An acute dermal toxicity study is available for a related substance (triethoxy-(2-methylpropyl)silane) in which the LD50 was >2000 mg/kg bw (Huntingdon Research Centre, 1987b), confirming the low acute toxicity of the substance; the relevance of this substance is discussed further in Section 7.5.
Key value for chemical safety assessment
Acute toxicity: via oral route
Endpoint conclusion
- Endpoint conclusion:
- no adverse effect observed
- Dose descriptor:
- LD50
- Value:
- 2 000 mg/kg bw
Acute toxicity: via inhalation route
Endpoint conclusion
- Endpoint conclusion:
- no adverse effect observed
- Dose descriptor:
- LC50
- Value:
- 11 000 mg/m³ air
Acute toxicity: via dermal route
Endpoint conclusion
- Endpoint conclusion:
- no study available
Additional information
Only one study was available for the oral route, which was a reliable, GLP and guideline-compliant study (Hüls Prüfinstitut für Toxikologie, 1993a). For the inhalation route there are two reliability score 2 studies. The key study was selected as the most recent of these and for which the appropriate exposure duration was used according to current guidelines.
Justification for selection of acute toxicity – oral endpoint
The selected study is the only acute oral toxicity study available for the registered substance. It was carried out in accordance with an appropriate OECD test guideline and in compliance with GLP.
Justification for selection of acute toxicity – inhalation endpoint
The selected study is the most recent and reliable acute inhalation toxicity study available for the registered substance. It was carried out in accordance with an appropriate OECD test guideline and in compliance with GLP.
Justification for classification or non-classification
The available results for the oral and inhalation routes do not trigger classification for lethality for trimethoxy(2-methylpropyl)silane according to Regulation (EC) No 1272/2008.
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.
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