Registration Dossier
Registration Dossier
Data platform availability banner - registered substances factsheets
Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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
Use of this information is subject to copyright laws and may require the permission of the owner of the information, as described in the ECHA Legal Notice.
EC number: 204-072-6 | CAS number: 115-21-9
- 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
![](https://poisoncentres.echa.europa.eu/o/diss-blank-theme/images/factsheets/A-REACH/factsheet/print_toxicological-information.png)
Endpoint summary
Administrative data
Description of key information
No adequate repeated dose toxicity data are available for trichloro(ethyl)silane, therefore data for the inhalation and oral routes have been read-across from the related substance, trimethoxy(methyl)silane, CAS 1185-55-3. Exposure to trimethoxy(methyl)silane (MTMS) was associated with organ weight and/or histomorphological changes in males (liver, thymus, thyroid, duodenum, jejunum, and red blood cell) and females (liver, thyroid, duodenum, jejunum, and adrenal gland) at dose levels at or above 250 mg/kg bw/day. A marked increase in prothrombin time was observed for males at 250 and 1000 mg/kg bw/day whereas females were unaffected. Exposure was also associated with increased blood platelet concentration for males and females at 1000 mg/kg bw/day. These data support a NOAEL for the toxicity phase of the study of 50 mg/kg bw/day.
There is also a 90-day inhalation study on trimethoxy(methyl)silane. Based on the increased incidence of grossly observed urinary bladder calculi along with the kidney dilation at the 400 ppm exposure level, the No Observable Adverse Effect Level (NOAEL) for trimethoxy(methyl)silane vapor administered six hours per day, five days per week for a 90-day interval via whole-body inhalation exposure to male and female Sprague-Dawley rats, was 100 ppm (equivalent to 557.14 mg/m3).
The key study (DCC, 2007) for repeated dose toxicity via the inhalation route, is a 90-day whole-body inhalation study, in which methyltrimethoxysilane was administered to rats six hours per day, five days per week. The NOAEC of 100 ppm (0.56 mg/l) was based on an increased incidence of grossly observed urinary bladder calculi along with kidney dilation at the 400 ppm exposure concentration.
An oral OECD 422 screening test in rats is available for the substance methyltrimethoxysilane. The NOAEL for systemic effects was determined to be 50 mg/kg/day, based on findings in a number of organs including the liver and thymus gland.
Key value for chemical safety assessment
Repeated dose toxicity: via oral route - systemic effects
Endpoint conclusion
- Dose descriptor:
- NOAEL
- 50 mg/kg bw/day
Repeated dose toxicity: inhalation - systemic effects
Endpoint conclusion
- Dose descriptor:
- NOAEC
- 560 mg/m³
Additional information
There are no adequate repeated dose toxicity data on trichloro(ethyl)silane or its hydrolysis product, ethylsilanetriol, so good quality data for the related substance methyltrimethoxysilane (MTMS) has been used to assess the general systemic toxicity of trichloro(ethyl)silane. Local effects from the other hydrolysis product, hydrogen chloride (HCl) are not addressed by these data.
Trichloro(ethyl)silane hydrolyses rapidly in contact with water (half-life <1 minute at pH 7), generating HCl and ethylsilanetriol. Methyltrimethoxysilane (MTMS, CAS 1185 -55 -3) hydrolyses more slowly at pH 7 (half-life ca. 2 hours), but under acidic conditions such as in the stomach following ingestion, much more rapid hydrolysis can be expected based on experience with other methoxysilanes. The relevant hydrolysis products are methanol and methylsilanetriol. The silanol hydrolysis products are therefore very similar in chemical structure, the only difference being the replacement of -C2H5 with -CH3. Both have high water solubility and very low log Kow (log Kow -1.9 and -2.4, respectively). They are therefore expected to have similar toxicological behaviour. Data obtained via the oral route for MTMS are therefore considered appropriate for read-across to trichloro(ethyl)silane with respect to systemic effects.
For the inhalation route, the hydrolysis rate of MTMS in the respiratory tract and lungs is unknown, but is likely to be slower than that of trichloro(ethyl)silane. For trichloro(ethyl)silane, the species absorbed following inhalation exposure are mainly hydrolysis products, whereas for MTMS, absorption of the parent substance may be more significant. MTMS has a higher log Kow value (0.7) therefore the proportion of inhaled material which is systemically absorbed is likely to be greater for MTMS than for trichloro(ethyl)silane. Nevertheless, in the absence of other data, the inhalatory NOAEL for MTMS is considered to represent a reasonable worst-case for read-across to trichloro(ethyl)silane.
It is of note that the oral NOAEL in rats for methanol is greater (500 mg/kg bw/day) than the dose that is expected to be generated from hydrolysis of trimethoxy(vinyl)silane in the stomach. Therefore the effects of trimethoxy(vinyl)silane following a dose of 62.5 mg/kg bw/day are not thought to be attributable to methanol. Similarly, following inhalation of methanol the NOAEC is an order of magnitude greater than the NOAEC for trimethoxy(vinyl)silane, and it is therefore unlikely that systemic effects observed following inhalation of trimethoxy(vinyl)silane are due to methanol.
Justification for classification or non-classification
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.
![ECHA](/o/diss-blank-theme/images/factsheets/A-REACH/factsheet/echa_logo.png)