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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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: 213-914-1 | CAS number: 1066-40-6
- 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
Basic toxicokinetics
Administrative data
- Endpoint:
- basic toxicokinetics in vivo
- Type of information:
- experimental study
- Adequacy of study:
- supporting study
- Study period:
- No data
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- other: The study was well documented and meets generally accepted scientific principles, but was not conducted in compliance with GLP.
Data source
Reference
- Reference Type:
- study report
- Title:
- Unnamed
- Year:
- 2 001
- Report date:
- 2001
Materials and methods
- Objective of study:
- metabolism
Test guideline
- Qualifier:
- no guideline followed
- Principles of method if other than guideline:
- The objectives of the study were to develop high-pressure liquid chromatography conditions to obtain profiles for the metabolites of MM in rat urine, and elucidate the structures of all the major metabolites.
- GLP compliance:
- no
Test material
- Reference substance name:
- Hexamethyldisiloxane
- EC Number:
- 203-492-7
- EC Name:
- Hexamethyldisiloxane
- Cas Number:
- 107-46-0
- Molecular formula:
- C6H18OSi2
- IUPAC Name:
- Hexamethyldisiloxane
Constituent 1
- Radiolabelling:
- other: 14C-MM
Test animals
- Species:
- rat
- Strain:
- Fischer 344
- Sex:
- female
Administration / exposure
- Route of administration:
- other: oral and IV
- Vehicle:
- unchanged (no vehicle)
- Duration and frequency of treatment / exposure:
- Single dose
Doses / concentrations
- Remarks:
- Doses / Concentrations:
Oral: 300 mg/kg bw
IV: 80 mg/kg bw
- No. of animals per sex per dose / concentration:
- 4 females for oral and 2 females for i.v.
- Control animals:
- no
Results and discussion
Main ADME results
- Type:
- metabolism
- Results:
- major metabolites identified: Me2Si(OH)2; HOMe2SiCH2OH; HOCH2Me2SiOSiMe2CH2OH (predominant); HOCH2Me2SiOSiMe3; HOMe2SiOSiMe3; Me3SiOH.
Metabolite characterisation studies
- Metabolites identified:
- yes
- Details on metabolites:
- The following are among the major metabolites identified: Me2Si(OH)2; HOMe2SiCH2OH; HOCH2Me2SiOSiMe2CH2OH (predominant); HOCH2Me2SiOSiMe3; HOMe2SiOSiMe3; Me3SiOH. Besides these there were also three other metabolites: HOMe2SiOSiMe2CH2OH; 2,2,5,5-tetramethyl-2,5-disila-1,3-dioxalene and 2,2,5,5-tetramethyl-1,4-dioxa-2,5-disilacyclohexane inferred from GC-MS analyses. Their presence in the HPLC metabolite profile was not established. No parent MM was present in urine.
Any other information on results incl. tables
The presence of certain metabolites such as Me2Si(OH)2; HOMe2SiCH2OH clearly establish some demethylation at the silicon-methyl bonds. Metabolites (abundant in hydroxymethyl groups) of this linear siloxane are structurally different from that obtained for cyclic siloxanes (D4 and D5, which are mainly silanols) except for the commonly present Me2Si(OH)2 (dimethylsilanediol).
Applicant's summary and conclusion
- Conclusions:
- Interpretation of results : no bioaccumulation potential based on study results
In a non-GLP study into the metabolism of hexamethyldisiloxane (reliability score 2), metabolites (abundant in hydroxymethyl groups) of this linear siloxane were found to be structurally different from that obtained for cyclic siloxanes (D4 and D5, which are mainly silanols) except for the commonly present dimethylsilanediol. - Executive summary:
In a non-GLP study into the metabolism of hexamethyldisiloxane (reliability score 2), metabolites (abundant in hydroxymethyl groups) of this linear siloxane were found to be structurally different from that obtained for cyclic siloxanes (D4 and D5, which are mainly silanols) except for the commonly present dimethylsilanediol.
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.