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EC number: 213-914-1 | CAS number: 1066-40-6
- 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 an inhalation OECD Test Guideline 422 screening study (WIL Research Laboratories, 2008), which was conducted to GLP, the NOAEC for trimethylsilanol was ≥600 ppm (2213.5 mg/m3).
In a 28-day oral repeated dose toxicity study (Bayer AG, 1986) conducted to OECD Test Guideline 407 and in compliance with GLP, the NOAEL for trimethylsilanol was 250 mg/kg bw/day.
Key value for chemical safety assessment
Repeated dose toxicity: via oral route - systemic effects
Endpoint conclusion
- Endpoint conclusion:
- no adverse effect observed
- Dose descriptor:
- NOAEL
- 250 mg/kg bw/day
- Study duration:
- subacute
- Species:
- rat
- Quality of whole database:
- There is only one oral repeated dose study available for which adequate study details are available for review. It was conducted according to OECD Test Guideline 407 and in compliance with GLP.
Repeated dose toxicity: inhalation - systemic effects
Endpoint conclusion
- Endpoint conclusion:
- no adverse effect observed
- Dose descriptor:
- NOAEC
- 2 213.5 mg/m³
- Study duration:
- subacute
- Species:
- rat
- Quality of whole database:
- The key study was conducted according to OECD Test Guideline 422 and in compliance with GLP. It was selected as the key study as it was conducted over the longest duration of exposure.
Repeated dose toxicity: inhalation - local effects
Endpoint conclusion
- Endpoint conclusion:
- no adverse effect observed
- Dose descriptor:
- NOAEC
- 2 213.5 mg/m³
- Study duration:
- subacute
- Species:
- rat
- Quality of whole database:
- The key study was conducted according to OECD Test Guideline 422 and in compliance with GLP.
Repeated dose toxicity: dermal - systemic effects
Endpoint conclusion
- Endpoint conclusion:
- no study available
Repeated dose toxicity: dermal - local effects
Endpoint conclusion
- Endpoint conclusion:
- no study available
Additional information
In an inhalation OECD Test Guideline 422 screening study (WIL Research Laboratories, 2008), which was conducted to GLP, trimethylsilanol-related effects were limited to changes in haematology (lower eosinophil and lymphocyte counts for males) and serum chemistry (higher alanine aminotransferase for males and toxicity phase females) at 600 ppm. These changes occurred in the absence of correlating histologic changes and were not considered to be adverse. Therefore, under the conditions of this screening study, an exposure level of 600 ppm (2213.5 mg/m3) was considered to be the NOAEC for trimethylsilanol. The NOAEC from this study was selected as the most appropriate starting point for the inhalation DNELs.
In a good quality 2-week dose range-finding study (WIL Research Laboratories, 2007), trimethylsilanol-related effects were limited to the 600 ppm exposure level and consisted of CNS/behaviour-related clinical signs of hypoactivity (males) and impaired equilibrium (females) and macroscopic findings of diffusely pale lungs. The NOAEL for trimethylsilanol administered to Sprague-Dawley rats by inhalation for 2 consecutive weeks was 300 ppm.
In an oral gavage study apparently conducted to OECD Test Guideline 407, groups of Wistar rats (5/sex/dose) were given daily doses of either 0 (castor oil vehicle only), 80, 250 and 750 mg/kg bw/day trimethylsilanol for 28 days. Clinical observations, food and water intake, body weights, organ weights, clinical chemistry, haematology, and histopathology were all recorded. Toxicologically relevant adverse effects (reduced body weight gain, reduced alkaline phosphatase, reduced glucose (males), increased liver weights (females), and increased adrenal weights (males), and minor deposits in the bile ducts) were observed at the highest dose of 750 mg/kg bw/day. The NOAEL was 250 mg/kg bw/day, as effects observed at this or the lower dose of 80 mg/kg bw/day, were not dose-dependent and often values were within the normal range for historical controls. The NOAEL from this study was selected as the starting point for dermal DNELs as it represents the most conservative starting point in the absence of dermal data.
Based on an oral 28 day repeated dose toxicity study conducted using a protocol similar to OECD 407 and in compliance with GLP the NOAEL for trimethylsilanol was 160 mg/kg bw/day based on clinical signs of toxicity (narcosis), decreased body weight gain, haematological effects, and/or organ weight effects (study report currently not available - results taken from Japanese language website).
Justification for classification or non-classification
Based on the available oral and inhalation studies, trimethylsilanol does not require classification for specific organ toxicity following repeated administration 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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