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EC number: 241-881-3 | CAS number: 17955-88-3
- 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:
- 1995-04-18 to 1995-05-03
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- guideline study with acceptable restrictions
Data source
Reference
- Reference Type:
- study report
- Title:
- Unnamed
- Year:
- 1 995
- Report date:
- 1995
Materials and methods
Test guideline
- Qualifier:
- according to guideline
- Guideline:
- OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)
- Version / remarks:
- 1981
- Deviations:
- yes
- Remarks:
- 1000 cells examined for PCE/NCE
- GLP compliance:
- yes
- Type of assay:
- micronucleus assay
Test material
- Reference substance name:
- 1,1,1,3,5,5,5-heptamethyl-3-octyltrisiloxane
- EC Number:
- 241-881-3
- EC Name:
- 1,1,1,3,5,5,5-heptamethyl-3-octyltrisiloxane
- Cas Number:
- 17955-88-3
- Molecular formula:
- C15H38O2Si3
- IUPAC Name:
- 2,2,4,6,6-pentamethyl-4-octyl-3,5-dioxa-2,4,6-trisilaheptane
- Test material form:
- other: liquid
Constituent 1
Test animals
- Species:
- mouse
- Strain:
- other: Crl: CD1 (ICR)BR
- Sex:
- male/female
- Details on test animals or test system and environmental conditions:
- TEST ANIMALS
- Source: Charles River Laboratories, United States
- Age at study initiation: 8 weeks old
- Weight at study initiation: 27.0-36.1 and 21.8-27.1 g for males and females, respectively
- Assigned to test groups randomly: [no/yes, under following basis: ]
- Fasting period before study:
- Housing: The animals were housed 7 per cage during quarantine and 3 to 5 during randomization.
- Diet: commercial diet, ad libitum
- Water: water, ad libitum
- Acclimation period: 7 days
ENVIRONMENTAL CONDITIONS
- Temperature (°F): 72 +/- 6 °F
- Humidity (%): 55 +/- 15 %
- Photoperiod (hrs dark / hrs light): 12/12
Administration / exposure
- Route of administration:
- intraperitoneal
- Vehicle:
- - Vehicle(s)/solvent(s) used: the test substance was administered undiluted, however saline was used as a vehicle control
- Lot/batch no. (if required): C271379 - Details on exposure:
- PREPARATION OF DOSING SOLUTIONS: 501, 1670, 2756, 3925 and 5010 mg/kg were administered to 3 males and 3 females per dose by intraperitoneal injections for the dose selection study. All animals were examined daily for signs of toxicity or mortality during the 3-day study period.
- Duration of treatment / exposure:
- 72 hours
- Frequency of treatment:
- Intraperitoneal injections were made at 24, 48 and 72 hours
- Post exposure period:
- Test animals and vehicle control animals were euthanised at 24, 48 and 72 hours after dosing for extraction of the bone marrow. Positive control animals were euthanised at 24 hours after dosing.
Doses / concentrations
- Remarks:
- Doses / Concentrations:
1253, 2505, 5010 mg/kg bw
Basis:
actual ingested
- No. of animals per sex per dose:
- Test group: 5 males and 5 females per dose
- Control animals:
- yes, concurrent vehicle
- Positive control(s):
- cyclophosphamide
- Justification for choice of positive control(s): no data
- Route of administration: oral gavage
- Doses / concentrations: 80 mg/kg bw
Examinations
- Tissues and cell types examined:
- Bone marrow
- Details of tissue and slide preparation:
- CRITERIA FOR DOSE SELECTION: Based on the results from dose range-finding study the maximum tolerated dose was concluded to be 5000 mg/kg bw and the chosen doses for the main study were 1253, 2505, 5010 mg/kg bw.
TREATMENT AND SAMPLING TIMES ( in addition to information in specific fields): Dosed were administered at 24, 48 and 72 hours. Samples were obtained at 24, 48 and 72 hours.
DETAILS OF SLIDE PREPARATION: The marrow was flushed from the bone and transferred to centrifuge tubes containing 3-5 mL bovine serum. Following centrifugation to pellet the tissue, the supernatant was removed by aspiration and portions of the pellet were spread on slides and air dried. The slides were fixed in methanol, and stained in May-Grunwald solution followed by Giemsa. The air-dried slides were coverslipped using Depex mounting medium.
METHOD OF ANALYSIS: The slides were scored for micronuclei and the polychromatic erythrocyte (PCE) to normochromatic erythrocyte (NCE) cell ratio. 1000 PCE were scored per animal. The frequency of micronucleated cells was expressed as percent micronucleated cells based on the total PCEs present in the scored optic field. The normal frequency of micronuclei in this strain is approximately 0.0-0.4 %. The frequency of PCEs versus NCEs was determined by scoring the number of PCEs and NCEs observed in the optic fields while scoring the first 1000 erythrocytes. - Evaluation criteria:
- A test article that induced neither a statistically significant dose response nor a statistically significant and reproducible increase at one dose lever was considered negative.
- Statistics:
- - ANOVA was performed on the proportion of cells with micronuclei per animal
- Tukey's Studentized range test was used at each harvest time to determine which dose groups were significantly different from the control group
Results and discussion
Test results
- Sex:
- male/female
- Genotoxicity:
- negative
- Toxicity:
- no effects
- Vehicle controls validity:
- valid
- Positive controls validity:
- valid
- Additional information on results:
- RESULTS OF RANGE-FINDING STUDY
- Dose range: 501, 1670, 2756, 3925 and 5010 mg/kg bw
- Clinical signs of toxicity in test animals: all animals appeared normal immediately after dosing and throughout the 3-day study period
- Evidence of cytotoxicity in tissue analyzed: the PCE/NCE ratio was unchanged in treated animals.
- Other: Based on the results the maximum tolerated dose was concluded to be 5000 mg/kg bw
RESULTS OF DEFINITIVE STUDY
- Induction of micronuclei (for Micronucleus assay): no significant increase in micronucleated PCEs was observed in any of the test animals at any of the harvest times.
- Ratio of PCE/NCE (for Micronucleus assay): mean PCE/NCE ration males 0.62; man PCE/NCE ratio female 0.53
- Appropriateness of dose levels and route: yes
- Statistical evaluation: no statistically significant increase in micronucleated cells in bone marrow polychromatic erythrocytes was observed.
Any other information on results incl. tables
Table 1: Summary of results on micronucleus data
Treatment |
Dose |
Harvest time (hours) |
Total % of micronucleated PCEs mean of 1000 per animal |
Mean ratio PCE/NCE |
|
Males |
Females |
||||
Vehicle |
Saline |
24 |
0.02 |
0.66 |
0.55 |
48 |
0.01 |
0.62 |
0.60 |
||
72 |
0.01 |
0.51 |
0.57 |
||
Positive control |
CP 80 mg/kg bw |
24 |
2.18 |
0.63 |
0.58 |
Test substance |
1253 mg/kg bw |
24 |
0.03 |
0.79 |
0.43 |
48 |
0.00 |
0.61 |
0.46 |
||
72 |
0.00 |
0.48 |
0.56 |
||
2505 mg/kg bw |
24 |
0.05 |
0.63 |
0.53 |
|
48 |
0.02 |
0.55 |
0.61 |
||
72 |
0.02 |
0.56 |
0.55 |
||
5010 mg/kg bw |
24 |
0.04 |
0.67 |
0.65 |
|
48 |
0.02 |
0.84 |
0.45 |
||
72 |
0.00 |
0.51 |
0.53 |
CP: cyclophosphamide
Applicant's summary and conclusion
- Conclusions:
- Interpretation of results: negative
1,1,1,3,5,5,5-Heptamethyl-3-octyltrisiloxane has been tested for ability to induce micronuclei in mouse bone marrow polychromatic erythrocytes, conducted according to OECD TG 474 with acceptable restrictions, and in compliance with GLP (CHV, 1995). No increase in the number of micronuclei was observed when test substance was administered by intraperitonal injection up to limit concentration. No toxicity to bone marrow was observed when evaluated by the ratio of polychromatic erythrocytes to normochromatic erythrocytes. Appropriate solvent and positive controls were included and gave expected results. It is concluded that the test substance is negative for the induction of micronuclei under the conditions of this study.
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