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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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: 262-061-1 | CAS number: 60111-54-8
- 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
Ecotoxicological Summary
Administrative data
Hazard for aquatic organisms
Freshwater
- Hazard assessment conclusion:
- no hazard identified
Marine water
- Hazard assessment conclusion:
- no hazard identified
STP
- Hazard assessment conclusion:
- no hazard identified
Sediment (freshwater)
- Hazard assessment conclusion:
- PNEC sediment (freshwater)
- PNEC value:
- 13.5 mg/kg sediment dw
- Assessment factor:
- 10
- Extrapolation method:
- assessment factor
Sediment (marine water)
- Hazard assessment conclusion:
- PNEC sediment (marine water)
- PNEC value:
- 1.35 mg/kg sediment dw
- Assessment factor:
- 100
- Extrapolation method:
- assessment factor
Hazard for air
Air
- Hazard assessment conclusion:
- no hazard identified
Hazard for terrestrial organisms
Soil
- Hazard assessment conclusion:
- no hazard identified
Hazard for predators
Secondary poisoning
- Hazard assessment conclusion:
- no potential to cause toxic effects if accumulated (in higher organisms) via the food chain
Additional information
3,3-Bis[(dimethylvinylsilyl)oxy]-1,1,5,5-tetramethyl-1,5-divinyltrisiloxane (ViM4Q, CAS 60111-54-8) is very poorly soluble in water (<10 ng/l) and has a predicted log Kow value of 9.0. The substance hydrolyses slowly in water (half-life >200 - 2000 h at pH 7, 1.9 – 6.6 h at pH 4, and 2.0 – 13.9 h at pH 9 and 20-25°C (QSAR).
Aquatic organisms are therefore likely to be exposed to extremely low dissolved concentrations of the substance in the environment.
In the sediment and soil compartments adsorption to particulate and organic matter will be high.
READ-ACROSS JUSTIFICATION
In order to reduce testing, read-across is proposed to fulfil up to REACH Annex IX requirements for the registered substance from substances that have similar structure and physicochemical properties. Ecotoxicological studies are conducted in aquatic medium or in moist environments; therefore the hydrolysis rate of the substance is particularly important since after hydrolysis occurs the resulting product has different physicochemical properties and structure.
The behaviour of ViM4Q in the environment is going to be dominated by the high partition coefficient (log Kow 9) and adsorption coefficient properties (log Koc 6) of the substance.
ViM4Q and the substances used as surrogate for read-across are part of the Reconsile Siloxanes Category. Substances in this group tend to have low water solubility, high adsorption and partition coefficients and slow degradation rates in the sediment compartment. For substances with a log Kow of 8 and above no effects are seen with aquatic organisms due to the substance low water solubility limiting the effects seen. In the environment, the substances will adsorb to particulate matter and will partition to soil and sediment compartments.
Additional information is given in a supporting report (Siloxane Category Report, PFA 2017) attached in Section 13 of the IUCLID dossier. The Siloxane Category report (PFA, 2017) addresses the Assessment Elements of the RAAF and, in addition to describing the siloxanes category, forms the RAAF justification report.
In the following paragraphs the read-across approach for ViM4Q is assessed for the surrogate substances taking into account structure, hydrolysis rate and physico-chemical properties.
Read-across from D6 to ViM4Q (Sediment toxicity)
ViM4Q and the surrogate substance dodecamethylcyclohexasiloxane (D6, CAS 540-97-6) are siloxanes with 5 silicon atoms and 6 silicon atoms respectively. The registration substance, ViM4Q, is a quaternary-branched structure of five Si atoms, with four terminal Si atoms linked to a central Si atom by Si-O-Si bonds. Each of the four terminal Si atoms is substituted by one vinyl and two methyl groups. The surrogate substance is a cyclic siloxane consisting of six Si atoms, each having two methyl branches and alternated by oxygen. ViM4Q and D6 have similar physicochemical properties: high molecular weight (432.89 and 444.92, respectively), low solubility (both insoluble at 7.0E-05 mg/l and 5.1E-03 mg/l, respectively), high log Kow (9 and 8.87, respectively) and high log Koc (6.0 and 5.9 respectively). Both substances have negligible biodegradability and hydrolysis rates. A comparison of the key physicochemical properties is presented in the table below.
No effects at the limit of solubility have been reported in short-term and long-term studies in other trophic levels conducted with both substances.
Given the similar properties and structural similarities, it is considered valid to read across sediment toxicity data from D6 to ViM4Q.
Read-across from D5 to ViM4Q (Sediment toxicity)
Decamethylcyclopentasiloxane (CAS 541-02-6, D5) is a cyclic siloxane with five Si having methyl groups and linked by oxygen atoms. The registered substance is a composite siloxane having a central siloxane with four oxygens each linking to another silicon with two methyl groups and a vinyl side chain. The registered substance has a total of 5 silicon atoms. Both the registered substance and D5 have similar physico-chemical properties: high molecular weight (432.89 and 370.78 respectively), high log Kow (9 and 8.07 respectively) and high log Koc (both 6). Both substances have negligible biodegradability and hydrolysis rates.
No effects at the limit of solubility have been reported in short-term and long-term studies in other trophic levels conducted with both substances. The registered substance and the surrogate substance share similar physico-chemical properties but are not close structural analogues (branched and cyclic siloxanes). However, given the similar properties and structural similarities, it is considered valid to read-across data from D5 to ViM4Q.
Table: Summary of ecotoxicological and physico-chemical properties for the registered substance and the surrogate substances.
CAS Number |
60111-54-8 |
541-02-6 |
540-97-6 |
Chemical Name |
3,3-Bis[(dimethylvinylsilyl)oxy]-1,1,5,5-tetramethyl-1,5-divinyltrisiloxane (ViM4Q) |
Decamethylcyclopentasiloxane (D5) |
Dodecamethylcyclehexasiloxane (D6) |
Main ultimate Si hydrolysis product |
Dimethylvinylsilanol1 |
Dimethylsilanediol |
Dimethylsilanediol |
Molecular weight (parent) |
432.89 |
370.78 |
444.92 |
Molecular weight (silanol hydrolysis product) |
102.2 |
92.17 |
92.17 |
Log Kow (parent) |
9.0 |
8.07 |
8.87 |
Log Kow (silanol hydrolysis product) |
1.5 |
-0.38 |
-0.38 |
Water solubility (parent) |
<10 ng/l |
0.017 mg/l |
0.0051 mg/l |
Water solubility (silanol hydrolysis product) |
n/a |
1.0E+06 mg/l |
1.0E+06 mg/l |
Vapour pressure (parent) |
<10 Pa |
33.2 Pa |
4.7 Pa |
Vapour pressure (hydrolysis product) |
n/a |
7 Pa |
7 Pa |
Hydrolysis t1/2 at pH 7 and 25°C |
>200 h |
1590 h |
>1 year |
Hydrolysis t1/2 at pH 4 and 25°C |
1.9 h |
9.3 h |
|
Hydrolysis t1/2 at pH 9 and 25°C |
2.0 h |
24.8 - 31.6 h |
|
Short-term toxicity to fish (LC50) |
>LoS (>14.2 ng/l) |
n/a |
n/a |
Short-term toxicity to aquatic invertebrates (EC50) |
>LoS (>19 ng/l) |
n/a |
n/a |
Algal inhibition (ErC50 and NOEC) |
>LoS (>15 ng/l) |
ErC50: >2.0 μg/l; NOEC: ≥2.0 μg/l |
EC50: >2.0 μg/l; NOEC: ≥2.0 μg/ |
Long-term toxicity to fish (NOEC) |
n/a |
≥4.4 μg/l |
≥4 μg/l(supporting, as bioaccumulation study) |
Long-term toxicity to aquatic invertebrates (NOEC) |
n/a |
≥4.6 µg/l |
≥4.6 µg/l |
Long-term toxicity to sediment organisms (NOEC) |
n/a |
70 mg/kg dwt, C. riparius; ≥1272 mg/kg dwt L. variegatus; 130 mg/kg dwt, H. azteca. |
<22 mg/kg dwt, C. riparius; ≥420 mg/kg dwt, L. variegatus; |
Short-term terrestrial toxicity (L/EC50) |
n/a |
(IC50) 209 mg/kg dwt, H. vulgare; >4054 mg/kg dwt, T. pratense |
n/a |
Long-term terrestrial toxicity (NOEC) |
≥1000 mg/kg dwt, Eisenia fetida; EC25 and EC50 >100 mg/kg dwt, soil microorganisms |
≥4074 mg/kg dwt, E. Andrei; 377 mg/kg dwt, F. candida |
n/a |
Notes
LoS = limit of solubility
1 – Silicic acid is also generated by the hydrolysis of the registration substance
Consideration of low functionality side chains and reactive groups
Vinyl group: From the available dataset in the whole of the silanes and siloxanes database, vinyl fragments are understood to not have any specific mode of action with respect to ecotoxicity. For example, trimethoxyvinylsilane (CAS 2768-02-7) is an alkoxysilane with vinyl groups and a log Kow 1.1. Short-term toxicity data for the substance report L(E)C50 values in the range >89-191 mg/l (Dow Corning 1979, Hüls 1993 and MOEC 2006), which are consistent with non-polar narcosis as seen with other alkoxysilanes.
Conclusion on classification
The submission substance is not classified for the environment in the EU according to the regulation (EC) No 1272/2008 because no short-term toxicity effects have been reported at the limit of solubility. In addition, the substance has a log Kow 9 and very low water solubility (<10 ng/l) and no structural alerts, therefore based on non-polar narcosis mechanism of toxicity, no toxicity is expected to be expressed at the limit of solubility.
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.