Registration Dossier
Registration Dossier
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: 213-603-0 | CAS number: 993-07-7
- 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
No sensitisation data are available for the registered substance. Data are available for the structural analogue, tetramethylsilane (CAS 75-76-3), from a skin sensitisation study, conducted in accordance with OECD 406 (Buehler method) and in compliance with GLP. Tetramethylsilane was not sensitising in the guinea pig (Hüls, 1998). No skin reactions were observed at challenge.
Information on tetramethylsilane is included for completeness only.
Key value for chemical safety assessment
Skin sensitisation
Endpoint conclusion
- Endpoint conclusion:
- no adverse effect observed (not sensitising)
- Additional information:
There are no measured data available to assess the skin sensitisation potential of trimethylsilane, and testing is not technically feasible because the substance is a gas. Therefore data for the structural analogue substance tetramethylsilane (CAS 75-76-3) has been used to assess its skin sensitisation potential. Tetramethylsilane was not sensitising (Hüls, 1998) when tested in the guinea-pig Buehler assay (OECD 406).
Information on tetramethylsilane is included for completeness only.
Read-across justification
To reduce animal testing REACH recommends to make use of a read-across approach where appropriate based on the high accordance in properties relevant for the specific endpoint. In the case of irritation the relevant properties are structural similarity as well as physical-chemical properties in the same range. In the following paragraphs the proposed read-across from triethylsilane to trimethylsilane is discussed. A report considering read across for all endpoints is attached in Section 13.
Read-across hypothesis
The hypothesis is that source and target substances have similar toxicological properties because they are structurally similar and have similar physicochemical properties. Trimethylsilane has a half-life in water of days and tetramethylsilane is hydrolytically stable, so reaction products do not need to be considered for the human health hazard assessment of these substances.
(a) Structural similarity
The registration and read-across substances are structurally similar and are members of an analogue group of alkylsilanes. The substances contain a silicon atom to which is attached three or four alkyl (methyl/ethyl) groups. For the registered substance there are three methyl groups, for tetramethylsilane there are four methyl group. The registered substance also has an Si-H group. There is no evidence that the Si-H group is sensitising.
(b) Similar physicochemical characteristics
The key physicochemical parameters are summarised below.
-
Target (registration substance)
Source (read-across substance
)CAS number
993-07-7
75-76-3
EC number
213-603-0
200-899-1
Chemical Name
Trimethylsilane
Tetramethylsilane
Molecular weight
(gmol-1)74.20
88.23
log Kow
2.2 at 20°C
2.7 at 20°C
Water solubility at 20°C
Estimated to be 1400 mg/l at 20°C, in practice the concentration is not expected to be achieved due to very high volatility of the substance
19.6 mg/l at 25°C
Vapour pressure
Not applicable (substance is a gas), expected to be greater than 1.0E+05 Pa
79 000 Pa at 20°C
Respiratory sensitisation
Endpoint conclusion
- Endpoint conclusion:
- no study available
Justification for classification or non-classification
Based on a reliable in vivo study on tetramethylsilane, trimethylsilane is not classified as a skin sensitiser according to Regulation (EC) No 1272/2008.
There are no data to suggest that trimethylsilane is a respiratory sensitiser.
To reduce animal testing REACH recommends to make use of a read-across approach where appropriate based on the high accordance in properties relevant for the specific endpoint. In the case of sensitisation, the relevant properties are physicochemical properties and structural similarity. In the following paragraphs the proposed read-across from tetramethylsilane to trimethylsilane is discussed. A report considering read across for all endpoints is attached in Section 13.
Read-across hypothesis
The hypothesis is that source and target substances have similar toxicological properties because they are structurally similar and have similar physicochemical properties. The substances are hydrolytically stable in the context of toxicological testing (trimethylsilane and tetramethylsilane have half-lives in water of days), so reaction products do not need to be considered for the human health hazard assessment of these substances.
Read-across justification
(a) The registration and read-across substances are structurally similar and are members of an analogue group of alkylsilanes. Both contain a silicon atom to which is attached three or four methyl groups. For the registered substance there are three methyl groups, for the read-across substance there are four. The registered substance also has an Si-H group. There is no evidence that the Si-H group is sensitising. It is therefore not considered likely that replacing Si-H with Si-CH3would be likely to confer additional skin sensitising properties on the registration substance; however, this cannot be demonstrated experimentally due to the physical state of trimethylsilane at ambient temperature and pressure.
(b) The key physicochemical parameters are summarised below.
Table: Key physicochemical parameters
|
Target (registration substance) |
Source substance (read-across) |
CAS number |
000993-07-7 |
000075-76-3 |
EC number |
213-603-0 |
200-899-1 |
Chemical Name |
Trimethylsilane |
Tetramethylsilane |
Molecular weight (gmol-1) |
74.20 |
88.23 |
log Kow (parent) |
2.2 |
2.7 |
Water solubility (parent) |
Estimated to be 1400 mg/l (QSAR), limited by condensation reactions following abiotic reaction to silanol |
19.6 mg/l |
Vapour pressure (parent) |
Not applicable (substance is a gas) |
79000 Pa at 20°C |
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.

EU Privacy Disclaimer
This website uses cookies to ensure you get the best experience on our websites.