Registration Dossier
Registration Dossier
Data platform availability banner - registered substances factsheets
Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.
The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.
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: 402-140-1 | CAS number: 17865-32-6 CHMMS; CHMS; DYNASYLAN 9407; Z-6187
- 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 germ cell study: cytogenicity / chromosome aberration
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Study period:
- 9 August 1988 to 30 November 1988
- Reliability:
- 1 (reliable without restriction)
- Rationale for reliability incl. deficiencies:
- guideline study
Data source
Reference
- Reference Type:
- study report
- Title:
- Unnamed
- Year:
- 1 989
- Report date:
- 1989
Materials and methods
Test guideline
- Qualifier:
- equivalent or similar to guideline
- Guideline:
- OECD Guideline 478 (Genetic Toxicology: Rodent Dominant Lethal Test)
- Deviations:
- no
- Principles of method if other than guideline:
- A 6-week dominant lethal study in mice
- GLP compliance:
- yes
- Type of assay:
- rodent dominant lethal assay
Test material
- Reference substance name:
- Cyclohexyldimethoxymethylsilane
- EC Number:
- 402-140-1
- EC Name:
- Cyclohexyldimethoxymethylsilane
- Cas Number:
- 17865-32-6
- Molecular formula:
- C9H20O2Si
- IUPAC Name:
- cyclohexyldimethoxymethylsilane
- Test material form:
- liquid
Constituent 1
Test animals
- Species:
- mouse
- Strain:
- CD-1
- Sex:
- male
- Details on test animals or test system and environmental conditions:
- TEST ANIMALS
- Source: Charles River Breeding Laboratories (UK), Margate, Kent, England
- Age at study initiation: no data
- Weight at study initiation: 24-31 g
- Assigned to test groups randomly: no data
- Fasting period before study: no data
- Housing:group-housed (4 or 5/cage) during acclimation and dosing, high density polypropylene cages with stainless steel tops
- Diet: ad libitum, laboratory animal diet LAD 1
- Water: ad libitum
- Acclimation period: at least 5 days prior to treatment
ENVIRONMENTAL CONDITIONS
- Temperature (°C): target 21, acceptable range 19-25
- Humidity (%): 55+/- 15
- Air changes (per hr): 15/hr
- Photoperiod (hrs dark / hrs light): 12 hr light/12 hr dark
IN-LIFE DATES: From: 19-Aug-1988 To:30-Nov-1988
Administration / exposure
- Route of administration:
- oral: gavage
- Vehicle:
- - Vehicle(s)/solvent(s) used: corn oil
- Justification for choice of solvent/vehicle: test material freely miscible with corn oil and adequately stable in corn oil over a 72-hr period
- Concentration of test material in vehicle: dosed at 10 ml/kg bw, so presumably 5-125 mg/ml
- Amount of vehicle (if gavage or dermal): 10 ml/kg bw
- Type and concentration of dispersant aid (if powder): not applicable
- Lot/batch no. (if required): no data
- Purity: no data - Details on exposure:
- PREPARATION OF DOSING SOLUTIONS: Required volumes of CHMMS violently mixed with corn oil initially during dose preparation. Inversion of the dose container employed prior to dosing to ensure maintenance of an adequate mixture and to minimise introduction of air bubbles.
DIET PREPARATION
not applicable - Duration of treatment / exposure:
- 6 weeks
- Frequency of treatment:
- Vehicle control and treatment groups treated 5 days/week for 5 weeks and daily for week 6; positive control group treated daily for 3 days during week 6.
- Post exposure period:
- Mating to untreated females (2 females/male) on day following final treatment, then repeated with fresh females seven days later and repeated until 3 separate weekly matings were completed
Doses / concentrations
- Remarks:
- Doses / Concentrations:
50, 250 or 1250 mg/kg bw/day (1250 mg/kg bw/day dose reduced to 750 mg/kg bw/day from Monday of week 3 onwards)
Basis:
actual ingested
- No. of animals per sex per dose:
- 25 males
- Control animals:
- yes, concurrent vehicle
- Positive control(s):
- ethylmethanesulphonate
- Justification for choice of positive control(s): guideline recommendation
- Route of administration: oral gavage
- Doses / concentrations: 200 mg/kg bw/day for 3 consecutive days during week 6
Examinations
- Tissues and cell types examined:
- Treated males were mated with untreated females and the pregnancy rate, pre-implantation loss and post-implantation loss assessed
- Details of tissue and slide preparation:
- CRITERIA FOR DOSE SELECTION: based on a preliminary toxicity test
TREATMENT AND SAMPLING TIMES ( in addition to information in specific fields): On the day following the final treatment, each male mouse was housed for mating with two virgin females. The individual males were re-caged with fresh females seven days later, and this was repeated until 3 separate weekly matings were completed. Females were inspected daily, in the mornings, during the mating period for the presence of vaginal plugs. Sixteen days after introduction to the males, the pregnant females were killed and examined for total implant number and early and late deaths. - Evaluation criteria:
- Comparisons were made between treated and vehicle control groups each week for pregnancy rate, average number of implants (live and dead) and proportions of total implants found dead. Vaginal plugs were recorded to identify mated females and comparisons were made between treated and control groups for the proportion of females found to be pregnant. The average number of implants, live or dead, was calculated for each individual male and for each individual female of the groups, non-pregnant females being excluded, and treated and control groups were compared. Counts of early and late deaths were combined and the proportion of total implants found dead was obtained for each male. Individual male values were then used to test the homogeneity of each group.
- Statistics:
- Proportion of pregnant females: The variation between each treated group and the vehicle control group was assessed by calculation of the term X2B and the significance of the difference between the groups determined from chi-squared distribution tables.
Average number of implants per male and per female: The values for the treated and control groups were compared using a computer-based calculation of the non-parametic Mann-Whitney "U" test.
Proportion of implants found dead per male: A modified chi-squared calculation was performed giving X2W values and subsequent pairwise comparisons of test and control groups were undertaken, with calculation of X2B values. Where X2W values for both groups were non-significant, the significance of any difference between the groups was assessed by consideration of X2B alone. Where one or both groups were not homogeneous, the variance ratio was calculated and the significance obtained from the tables of the variance ratio distribution.
Results and discussion
Test results
- Sex:
- male
- Genotoxicity:
- negative
- Toxicity:
- yes
- Remarks:
- Overt signs of toxicity and death in a single male at the top dose level
- Vehicle controls validity:
- valid
- Negative controls validity:
- not examined
- Positive controls validity:
- valid
- Additional information on results:
- RESULTS OF RANGE-FINDING STUDY
- Dose range: 500, 750, 1250 or 2000 mg/kg bw/day
- Clinical signs of toxicity in test animals: A single male in the top dosed group was killed in extremis, showing general lethargy and hind-limb paralysis, after receiving its sixth treatment. At this time and on later days of treatment, the remaining 3 animals of this group showed hyperactivity and/or partial hind-limb paralysis (transient, with full recovery by the morning after each dose). A single male dosed at 1250 mg/kg bw/day, also showed partial hind-limb paralysis on the last day of dosing. No other significant treatment-related effects were observed.
- Rationale for exposure: With the exception of a single male dosed at 2000 mg/kg bw/day, surviving males impregnated both of the two females with which they were caged during the subsequent mating period. Based on these findings and the overt toxicity seen, a maximum dosage of 1250 mg/kg bw/day was selected for the main study.
RESULTS OF DEFINITIVE STUDY
- Appropriateness of dose levels and route: The maximum level of CHMMS administration employed was sufficient to produce overt toxicity, demonstrating that the test material was absorbed.
- Statistical evaluation: There were no statistically significant effects on pregnancy rate, pre-implantation loss or post-implantation loss in any of the CHMMS treated groups.
Any other information on results incl. tables
During week 2 of dosing, males given 1250 mg/kg bw/day showed transient ataxia, loss of gripping reflex and other behavioural abnormalities. The effects included a brief period of hyperactivity post-dose, followed by ataxia and, in some cases, apparent deep sedation. Recovery was complete within 3 -4.5 hours of dosing. A single male of this group was found dead at the end of week 2. After reducing the dose to 750 mg/kg bw/day, some animals showed post-dose hyperactivity during weeks 3 and 4, and ataxia and prominent testes were also observed. No obvious signs of adverse reactions were seen at the mid- and low-dose levels.
Table: Summary of group data
Treatment group |
Mating week |
Pregnant females |
Total implants |
Dead implants |
Mutagenic indexb |
|||
No. |
%a |
No. |
Mean/female |
No. |
Mean/female |
|
||
Vehicle controls (corn oil) |
1 2 3 |
48 46 46 |
96 92 92 |
559 577 568 |
11.6 12.5 12.3 |
32 24 26 |
0.7 0.5 0.5 |
5.7 4.2 4.6 |
CHMMS, 50 mg/kg bw/day |
1 2 3 |
42 47 48 |
91 94 96 |
529 573 566 |
12.6 12.2 11.8 |
29 30 41 |
0.7 0.6 0.9 |
5.5 5.2 7.2 |
CHMMS, 250 mg/kg bw/day |
1 2 3 |
43 46 46 |
86 92 92 |
524 555 546 |
12.2 12.1 11.9 |
23 30 26 |
0.5 0.7 0.6 |
4.4 5.4 4.8 |
CHMMS, 1250-750 mg/kg bw/day |
1 2 3
|
39 44 39 |
89 92 81 |
461 555 456 |
11.8 12.6 11.7 |
29 18 25 |
0.7 0.4 0.6 |
6.3 3.2 5.5 |
EMS, 200 mg/kg bw/day |
1 2 3 |
43 26 43 |
86 52** 86 |
398 246 507 |
9.3 9.5* 11.8 |
200 100 41 |
4.7 3.8 1.0 |
50.3** 40.7** 8.1* |
a - Percentage of all females caged with surviving, treated males and later confirmed as pregnant.
b - Mutagenic Index = (Total dead implants/total implants) x 100
* - Significantly different from Group 1 value, p<0.05 (based on "per male" analysis)
** - Significantly different from Group 1 value, p<0.001
Applicant's summary and conclusion
- Conclusions:
- In a well-conducted dominant lethal test, using a protocol similar to OECD Test Guideline 478 and in compliance with GLP, there was no evidence of germ cell mutation in mice after oral dosing of cyclohexyldimethylmethylsilane at up to 1250 mg/kg bw/day, a toxic dose.
- Executive summary:
A well-conducted dominant lethal test was performed using a protocol similar to OECD Test Guideline 478 and in compliance with GLP.
Groups of 25 male mice were given oral gavage doses of 50, 250 or 1250 mg cyclohexyldimethylmethylsilane/kg bw/day, 5 days/week for 5 weeks and 7 days/week during the 6th week. The highest tested dose level was reduced to 750 mg/kg bw/day from the beginning of the 3rd week of dosing following marked adverse reactions to treatment (hyperactivity, ataxia and sedation). A control group received vehicle only (corn oil) and a positive control group received ethylmethanesulphonate at 200 mg/kg bw/day on the last 3 days of week 6.
On the day following the last day of dosing, each male was individually caged with 2 virgin females and allowed to mate; evidence of mating was inspected daily. After 7 days, the females were removed and replaced with fresh virgin females. This process was repeated once more to give a total of 3, 1-week mating periods. Sixteen days after introduction to the males, each group of females was killed and the numbers of live and dead (early or late death) implants were recorded. Three separate parameters were investigated: pregnancy rate, pre-implantation loss and post-implantation loss.
There was no evidence of germ cell mutation in mice after oral dosing with cyclohexyldimethylmethylsilane at up to 1250 mg/kg bw/day, a toxic dose. A clear positive response was seen with the positive control.
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.