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EC number: 242-042-4 | CAS number: 18162-48-6
- 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

Genetic toxicity: in vivo
Administrative data
- Endpoint:
- in vivo mammalian somatic cell study: cytogenicity / bone marrow chromosome aberration
- Type of information:
- experimental study
- Adequacy of study:
- supporting study
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- comparable to guideline study with acceptable restrictions
- Remarks:
- The restrictions were the number of cells evaluated to determine mitotic index deviated from guideline, and reporting wes less detailed than the current guideline stipulatess.
Data source
Reference
- Reference Type:
- study report
- Title:
- Unnamed
- Year:
- 1 982
- Report date:
- 1982
Materials and methods
Test guideline
- Qualifier:
- equivalent or similar to guideline
- Guideline:
- OECD Guideline 475 (Mammalian Bone Marrow Chromosome Aberration Test)
- Deviations:
- yes
- Remarks:
- Number of cells evaluated, detail of reporting
- Principles of method if other than guideline:
- Rodent Bone Marrow Cytogenetic Assay as recommended by the Ad Hoc Committee on Chromosome Methodologies in Mutagen Testing (Toxicology & Applied Pharm 22: 269-275, 1972) with modifications per the EPA Gene-Tox Program Cytogenetics Committee (12/3 to 12/5, 1980, Washington, D.C.).
Studies were conducted in accordance with the recommendations of an ad hoc committee on chromosome methodologies in mutagen testing (EMS/IMR, 1972). - GLP compliance:
- yes
- Remarks:
- with no documenting of raw data from range finding, or quarantine or pre-trial healt of animals
- Type of assay:
- chromosome aberration assay
Test material
- Reference substance name:
- Chlorotrimethylsilane
- EC Number:
- 200-900-5
- EC Name:
- Chlorotrimethylsilane
- Cas Number:
- 75-77-4
- Molecular formula:
- C3H9ClSi
- IUPAC Name:
- chloro(trimethyl)silane
Constituent 1
Test animals
- Species:
- rat
- Strain:
- Sprague-Dawley
- Sex:
- male
- Details on test animals or test system and environmental conditions:
- Weight at study initiation: 250-320 g for range finding; approximately 280 g for cytogenetics study
TEST ANIMALS
- Source: Gofmor Farms Westboro MA USA (range finding); Charles River Laboratories, Wilmingtom MA USA
- Age at study initiation: no information
- Weight at study initiation: 250-320 g for range finding; approximately 280 g for cytogenetics study
- Assigned to test groups randomly: [no/yes, under following basis: ]
- Fasting period before study: no information
- Housing: 6-7 per cage
- Diet (e.g. ad libitum): no information
- Water (e.g. ad libitum): no information
- Acclimation period: no information
ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20
- Humidity (%): 50
- Air changes (per hr): no information
- Photoperiod (hrs dark / hrs light): no information
IN-LIFE DATES (from beginning of cytogenetic study): From: 1981-06-02 To: 1981-09-28
Administration / exposure
- Route of administration:
- intraperitoneal
- Vehicle:
- Vehicle = Negative control: Paraffin oil;
The negative control, paraffin oil, was used in each assay, as recommended by sponsor - Duration of treatment / exposure:
- 6, 24 or 48 hours
- Frequency of treatment:
- One i.p. injection/rat
- Post exposure period:
- 6, 24 or 48 hours
Doses / concentrationsopen allclose all
- Dose / conc.:
- 10 mg/kg bw/day (nominal)
- Dose / conc.:
- 19 mg/kg bw/day (nominal)
- Dose / conc.:
- 37 mg/kg bw/day (nominal)
- Dose / conc.:
- 74 mg/kg bw/day (nominal)
- No. of animals per sex per dose:
- First range-finding: 2 animals/dose group;
Second range-finding: 10 animals/dose group;
Cytogenetic studies: 6 animals/dose group/time point to achieve the minimum number of 5 animals per dose for analysis - Control animals:
- yes, concurrent vehicle
- Positive control(s):
- Cyclophosphamide (22 mg/kg)
Examinations
- Tissues and cell types examined:
- Suitable cell spreads were those with both properly condensed and well-spread chromosomes. A minimum of 100 metaphase cells was evaluated per animal.
- Details of tissue and slide preparation:
- Rats were sacrificed at the scheduled times and bone marrow was aspirated from the femur.
Approximately four slides were prepared from each animal.
Slides were fixed, stained and permanently mounted.
Suitable cells were photographed using a 100X objective.
Suitable spreads consisted of those which had both properly condensed and well-spread chromosomes.
In general, a minimum of 100 metaphase cells was analyzed per animal, and 5 animals were analyzed for each dose.
The choice of animals to be used for analysis was based on the quality of the slides. - Statistics:
- A comparison of the expected and observed distribution values was performed using the Chi2 test as a measure of "goodness of fit". The
Wilcoxon test was used as a non-parametric test to compare the distribution of breaks per animal between the negative control animals
and the highest test doses.
Results and discussion
Test results
- Sex:
- male
- Genotoxicity:
- negative
- Toxicity:
- yes
- Remarks:
- deaths occurred at doses of 45 mg/kg and above
- Vehicle controls validity:
- valid
- Negative controls validity:
- not applicable
- Positive controls validity:
- valid
- Additional information on results:
- Mortality indicated in range-finding studies
Any other information on results incl. tables
The doses used in the cytogenetic study were based on the range-finding experiments. In the first study, all animals dosed with 3672, 918, and 367 mg/kg and 1 of 2 animals dosed with either 93 or 37 mg/kg died within three days. In the second study, 3 of 10 animals dosed with 90 mg/kg died and 2 of 10 animals dosed with 45 mg/kg died. None of the other animals died.
For the cytogenetic experiments, four target doses were chosen: 74, 37, 19 and 10 mg/kg. Since all the animals lived, the top three dosage groups were chosen for analysis.
There was no evidence that silane, chlorotrimethyl- induced chromosomal damage in rats following IP injection, including complex rearrangements. COntrol values were comparable to historical controls. A summary of the total number of cells analyzed for each dose at each time of sacrifice in provided in the table below:
Summary of Chromosome Aberration Data at three respective intervals
Test Chemical |
Dose (mg/kg) |
No. of cells |
Gaps |
Breaks |
Other |
% Abnormal Cells |
Paraffin oil (1 ml): • at 6 hours • at 24 hours* • at 48 hours |
-- -- -- |
497 622 586 |
3 17 4 |
2 6 9 |
0 0 0 |
0.40 0.96 1.54 |
Silane, chlorotrimethyl-: • at 6 hours • at 24 hours • at 48 hours |
19 37 74 19 37 74 19* 37* 74 |
542 548 521 398 549 548 501 410 523 |
5 2 5 3 7 6 16 3 11 |
2 1 9 1 3 4 6 8 12 |
0 0 0 0 0 0 0 0 0 |
0.37 1.28 1.73 0.25 0.55 0.73 1.20 1.95 2.29 |
Cyclophosphamide • at 24 hours |
22 |
523 |
ND |
>65 |
7 quads |
* Chromosomal preparations of bone marrow cells could be made only from four animals.
ND = not determined
Quad = quadriradial
No complex rearrangements such as quadriradials, triradials, or ring chromosomes were detected in animals injected with the test substance.
A comparison of the frequencies of breaks for doses of silane, chlorotrimethyl- with the negative control at the three time points shows no significant differences. These frequencies are similar to those recorded for control animals in previous testing. The frequency of breaks in previous negative control animals ranged from 0 to 2.6%, a range compatible with all the results obtained in this project. The conclusion based on comparison to historical data is confirmed by a statistical analysis using the Wilcoxon test that demonstrated that there was no difference between the number of breaks per animal for the negative control groups and the test groups. The use of the Chi2 test as a measure of “goodness to fit” indicated that the distribution of breaks per animal closely followed the Poisson distribution.
The animals injected with cyclophosphamide (positive control) had both a large number of breaks and complex rearrangements.
Applicant's summary and conclusion
- Conclusions:
- Chloro(trimethyl)silane has been tested in a reliable assay according to a protocol that is similar to OECD Test Guideline 475 and in compliance with GLP. Appropriate concurrent negative and positive controls were included, and the expected responses were observed. The test substance, chloro(trimethyl)silane (CAS No. 75-77-4), did not cause an increase in the frequency of chromosomal breaks or aberrations in bone marrow cells of rats. Thus, there was no evidence in this study that it caused chromosomal damage.
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