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EC number: 209-136-7 | CAS number: 556-67-2
- 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:
- key study
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- comparable to guideline study with acceptable restrictions
- Remarks:
- The restrictions were that after exposure by inhalation for 6h per day for 5 days, sampling was carried out at 6 and 24 hours only; only 500 cells were scored to determine mitotic index.
Data source
Referenceopen allclose all
- Reference Type:
- study report
- Title:
- Unnamed
- Year:
- 1 994
- Report date:
- 1994
- Reference Type:
- publication
- Title:
- No information
- Author:
- Vergnes et al.
- Year:
- 2 000
- Bibliographic source:
- Environ. Molec. Mutagen. 36, 13-21
Materials and methods
Test guideline
- Qualifier:
- equivalent or similar to guideline
- Guideline:
- OECD Guideline 475 (Mammalian Bone Marrow Chromosome Aberration Test)
- Deviations:
- yes
- Remarks:
- inhalation study, sampling times differ from recommended times
- Principles of method if other than guideline:
- Handbook of in vivo toxicity testing Arnold et al Academic press, New York NY.
- GLP compliance:
- yes
- Type of assay:
- micronucleus assay
Test material
- Reference substance name:
- Octamethylcyclotetrasiloxane
- EC Number:
- 209-136-7
- EC Name:
- Octamethylcyclotetrasiloxane
- Cas Number:
- 556-67-2
- Molecular formula:
- C8H24O4Si4
- IUPAC Name:
- 2,2,4,4,6,6,8,8-octamethyl-1,3,5,7,2,4,6,8-tetroxatetrasilocane
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: Harlan Sprague Dawley
- Age at study initiation: 5 weeks
- Weight at study initiation: 213-242 g (males); 135-163 g (females)
- Assigned to test groups randomly: yes
- Fasting period before study: no
- Housing: individually in stainless steel wire mesh cages
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: 2 weeks
ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18-22
- Humidity (%): 40-70 %
- Air changes (per hr): no information
- Photoperiod (hrs dark / hrs light): 12 hours
IN-LIFE DATES: From: 10 August 1993 To: 2 October 1993
Administration / exposure
- Route of administration:
- inhalation
- Vehicle:
- Vehicle: air
- Details on exposure:
- TYPE OF INHALATION EXPOSURE: whole body
GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: Wahmann inhalation chambers 101 x 101 x 60 cm, rectangular with pyramidal top and bottom; volume 900 l
- Source and rate of air: no information
- Method of conditioning air: filtered
- System of generating vapour: liquid D4 from a piston pump into heated glass evaporation chamber
- Temperature, humidity, pressure in air chamber:
- Air flow rate: approx 200 l/minute
- Air change rate: 13-14 air changes per hour
- Treatment of exhaust air: no information
TEST ATMOSPHERE
- Brief description of analytical method used: concentration in exposure chamber was monitored by flame ionization gas chromatography
- Samples taken from breathing zone: no information - Duration of treatment / exposure:
- 6 h/d
- Frequency of treatment:
- Once per day for 5 days
- Post exposure period:
- 24 hours
Doses / concentrations
- Remarks:
- Doses / Concentrations:
0, 720 ppm (actual mean)
Basis:
analytical conc.
- No. of animals per sex per dose:
- 5
- Control animals:
- yes, concurrent vehicle
- Positive control(s):
- - Positive control substance: cyclophosphamide monohydrate
- Justification for choice of positive control(s): none given
- Route of administration: ip injection
- Doses / concentrations: 30 mg.kg bw
Examinations
- Tissues and cell types examined:
- Bone marrow
- Details of tissue and slide preparation:
- CRITERIA FOR DOSE SELECTION: maximum achievable concentration of vapour.
TREATMENT AND SAMPLING TIMES ( in addition to information in specific fields): Animals were treated with Colchicine (4 mg/kg ip) 2-3 hours before sacrifice.
DETAILS OF SLIDE PREPARATION: Bone marrow cells were incubated for 20-30 minutes in hypotonic solution and then fixed with 3:1 methanol:acetic acid. Drops were air dried onto slides which were stained with Giesma. Additional slides were prepared as needed to ensure sufficient numbers of mitotic cells were available for analysis.
METHOD OF ANALYSIS: 5 animals per sex per treatment group per sampling time were selected for evaluation. Where possible, 100 cells per animal were scored for incidence and type of chromosome aberration.
OTHER: 500 cells per animal were scored to determine mitotic index. - Evaluation criteria:
- A response is positive if there is a statistically significant exposure related increase in incidence of chromosomal aberrations.
- Statistics:
- Mann and Whitney's U-test.
Results and discussion
Test results
- Sex:
- male/female
- Genotoxicity:
- negative
- Toxicity:
- no effects
- Remarks:
- in bone marrow
- Vehicle controls validity:
- valid
- Negative controls validity:
- not applicable
- Positive controls validity:
- valid
- Additional information on results:
- Positive control test substance cyclophosphamide induced markedly increased incidence of chromosomal aberrations in males and females.
Any other information on results incl. tables
There was a slight reduction in weight gain (males) or in body weight (females). There was no significant of dose-related increase in the incidence of chromosomal aberrations in rats exposed to D4 vapour. Table 1 Induction of chromosomal aberrations in rat bone marrow
Dose |
0 |
700 ppm (6 hour) |
700 ppm (24 hour) |
Positive control |
Number of animals |
5 |
5 |
5 |
6 |
Cells counted |
500 |
500 |
500 |
586 |
Total number of aberrant cells |
2 |
5 |
6 |
99 |
Percentage aberrant cells |
0.4 |
1.0 |
1.2 |
16.9 |
Applicant's summary and conclusion
- Conclusions:
- Octamethylcyclotetrasiloxane has been tested under GLP in a valid study which was conducted according to a protocol that is similar to OECD 475 and in compliance with GLP. There was no statistically significant increase in chromosome aberrations in rat bone marrow cells as a result of exposure to the test substance. It is concluded that Octamethylcyclotetrasiloxane is negative for clastogenicity (induction of chromosome aberrations) in rats under the conditions of the test.
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