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EC number: 211-656-4 | CAS number: 681-84-5
- 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 / erythrocyte micronucleus
- Remarks:
- Type of genotoxicity: chromosome aberration
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Study period:
- 1987-03-23 - 1987-08-04
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- other: The study was conducted according to an appropriate OECD test guideline, with acceptable restrictions. The restrictions were that the report lacked details and only 1000 PCEs were scored for micronuclei. The study was compliant with GLP.
Data source
Reference
- Reference Type:
- study report
- Title:
- Unnamed
- Year:
- 1 987
- Report date:
- 1987
Materials and methods
Test guideline
- Qualifier:
- according to guideline
- Guideline:
- OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)
- GLP compliance:
- yes
- Type of assay:
- micronucleus assay
Test material
- Reference substance name:
- Tetramethyl orthosilicate
- EC Number:
- 211-656-4
- EC Name:
- Tetramethyl orthosilicate
- Cas Number:
- 681-84-5
- Molecular formula:
- C4H12O4Si
- IUPAC Name:
- tetramethyl silicate
Constituent 1
Test animals
- Species:
- rat
- Strain:
- Sprague-Dawley
- Sex:
- male/female
- Details on test animals or test system and environmental conditions:
- TEST ANIMALS
- Source: cannot be read in report
- Age at study initiation: not stated in report
- Weight at study initiation: animals were weighed, but weights are not recorded in the study report.
- Assigned to test groups randomly: yes
- Fasting period before study: none
- Housing: individually
- Diet (e.g. ad libitum): ad libitum except during exposure period
- Water (e.g. ad libitum): ad libitum except during exposure period
- Acclimation period: no information
ENVIRONMENTAL CONDITIONS
Procedures outlined in "Standard operating procedures for the Acute toxicology laboratory" were adhered to, but details are not given in the study report.
Administration / exposure
- Route of administration:
- inhalation: vapour
- Vehicle:
- - Vehicle(s)/solvent(s) used: air
- Justification for choice of solvent/vehicle: none given
- Concentration of test material in vehicle: 30 ppm - Details on exposure:
- TYPE OF INHALATION EXPOSURE: whole body
GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: Air/vapour mixture passed directly into an inlet port at top of 450 litre stainless steel and glass exposure chamber.
- Method of holding animals in test chamber: animals loose in chamber, on two planes of 10 rats per plane.
- Source and rate of air: not stated in report
- Method of conditioning air:
- System of generating particulates/aerosols: J-shaped glass generating tube with glass beads by a low flow FMI laboratory pump.
- Temperature, humidity, pressure in air chamber: not stated in report
- Air flow rate:
- Air change rate:
- Method of particle size determination:
- Treatment of exhaust air:
TEST ATMOSPHERE
- Brief description of analytical method used:
- Samples taken from breathing zone: yes/no - Duration of treatment / exposure:
- 4 hours
- Frequency of treatment:
- once
- Post exposure period:
- 24, 48 and 72 hours sacrifice times
Doses / concentrations
- Remarks:
- Doses / Concentrations:
30 ppm
Basis:
other: Acute vapour inhalation
- No. of animals per sex per dose:
- Five animals per sex per time period
- Control animals:
- yes
- Positive control(s):
- _ Positive control substance: cyclophosphamide
- Justification for choice of positive control(s): none stated, but standard positive control substance
- Route of administration: single ip injection
- Doses / concentrations: 25 mg/kg bw
Examinations
- Tissues and cell types examined:
- Femoral bone marrow
- Details of tissue and slide preparation:
- CRITERIA FOR DOSE SELECTION: limit dose
TREATMENT AND SAMPLING TIMES ( in addition to information in specific fields): 30 ppm - 24, 48 and 72 hours. Negative control 24 and 72 hours. Positive control 48 hours.
DETAILS OF SLIDE PREPARATION: Following centrifugation in 2ml foetal bovine serum, portions of the pellet were spread on slides, two slides per animal per sample time. Slides were air dried for an hour prior to fixing in methanol for five minutes then air dried. Slides were stained with a fluorescent stain, Acridine Orange, diluted with Sorensens phosphate buffer (pH 6.8) for four minutes. Slides were rinsed in three changes of Sorensens phosphate buffer for nine minutes. Coverslips were then sealed on the slides.
METHOD OF ANALYSIS: slides were coded and anlaysed in a blind study. 1000 PCE's were scored per animal and the frequency of micronuclei was determined as the number of polychromatic erythrocytes containing one or more micronuclear inclusion bodies per thousand PCE's. - Evaluation criteria:
- None stated in report
- Statistics:
- Statistical analysis was performed using the Wilcoxon Rank-Sum test.
Results and discussion
Test results
- Sex:
- male/female
- Genotoxicity:
- negative
- Toxicity:
- not specified
- Remarks:
- the NCE/PCE ratio was variable due to difficulty in scoring NCEs.
- Vehicle controls validity:
- valid
- Negative controls validity:
- not valid
- Positive controls validity:
- valid
- Additional information on results:
- RESULTS OF RANGE-FINDING STUDY
- Dose range:
- Solubility:
- Clinical signs of toxicity in test animals:
- Evidence of cytotoxicity in tissue analyzed:
- Rationale for exposure:
- Harvest times:
- High dose with and without activation:
- Other:
RESULTS OF DEFINITIVE STUDY
- Types of structural aberrations for significant dose levels (for Cytogenetic or SCE assay):
- Induction of micronuclei (for Micronucleus assay):
- Ratio of PCE/NCE (for Micronucleus assay):
- Appropriateness of dose levels and route:
- Statistical evaluation:
Any other information on results incl. tables
Micronuclear response of male and female rate
Dose |
Male/female |
Sampling time (hours) |
Mean number of PCE |
Mean number of PCE with MN |
Mean % of MN |
Vehicle* control |
Male |
24 |
1004.20 |
2.60 |
0.26 |
Vehicle control* |
Female |
24 |
1027.20 |
3.80 |
0.38 |
30 ppm |
Male |
24 |
1008.00 |
1.80 |
0.18 |
30 ppm |
Female |
24 |
1009.20 |
1.60 |
0.16 |
Positive control |
Male |
48 |
1009.40 |
60.2 |
5.62** |
Positive control |
Female |
48 |
1009.20 |
67.20 |
6.24** |
30 ppm |
Male |
48 |
1010.80 |
1.40 |
0.14 |
30 ppm |
Female |
48 |
1006.40 |
1.20 |
0.12 |
Vehicle* control |
Male |
72 |
1003.40 |
1.60 |
0.16 |
Vehicle* control |
Female |
72 |
1005.40 |
1.20 |
0.12 |
30 ppm |
Male |
72 |
1004.60 |
2.20 |
0.22 |
30 ppm |
Female |
72 |
1009.60 |
1.40 |
0.14 |
*Vehicle control: sham exposed to air
** Statistically significant at the % confidence interval (p<0.05)
Applicant's summary and conclusion
- Conclusions:
- Interpretation of results (migrated information): negative
Tetramethyl orthosilicate was tested in an in vivo rat micronucleus assay according to OECD 474, and in compliance with GLP. No evidence of a test substance mediated induction of micronuclei was observed following inhalation exposure to the maximum tolerated dose. It was noted that the NCE/PCE ratio was variable due to difficulty in scoring NCEs. It is concluded that the test substance is not genotoxic under the conditions of the test.
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