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EC number: 219-842-7 | CAS number: 2550-02-9
- 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
Endpoint summary
Administrative data
Key value for chemical safety assessment
Genetic toxicity in vitro
Description of key information
No measured data are available to assess the genotoxic potential of the
registered substance, triethoxypropylsilane, however, reliable data are
available for the following structural analogue substances:
trimethoxypropylsilane (CAS 1067-25-0), trimethoxymethylsilane (CAS
1185-55-3), and triethoxyoctylsilane (CAS 2943-75-1).
WoE approach CAS 1067-25-0 and CAS 2943-75-1: Gene mutation (Bacterial
reverse mutation assay / Ames test): negative with and without metabolic
activation in Salmonella typhimurium strains: TA 98, TA, 100, TA 1535,
TA 1537 and Escherichia coli strain: WP2 uvrA (according to OECD TG 471).
WoE approach CAS 1185-55-3 and CAS 2943-75-1: Mutagenicity in vitro in
mammalian cells: positive with metabolic activation in mouse lymphoma
L5178Y cells with the structural analogue substance
trimethoxymethylsilane (CAS: 1185-55-3) and negative with and without
metabolic activation in mouse lymphoma L5178Y cells with the structural
analogue subtance triethoxyoctylsilane (CAS: 2943-75-1) (according to
OECD TG 476).
WoE approach CAS 1185-55-3 and CAS 2943-75-1: Cytogenicity in in vitro
mammalian cells: positive with metabolic activation in CHO cells with
the structural analogue substance trimethoxymethylsilane (CAS 1185-55-3)
and negative with and with metabolic activation in CHO cells with the
structural analogue substance triethoxyoctylsilane (CAS 2943-75-1)
(according to OECD TG 473).
Link to relevant study records
- Endpoint:
- in vitro gene mutation study in bacteria
- Type of information:
- read-across from supporting substance (structural analogue or surrogate)
- Remarks:
- Summary of available data used for the endpoint assessment of the target substance
- Adequacy of study:
- key study
- Justification for type of information:
- Please refer to the attached justification below and the overall justification for grouping of substances attached in IUCLID Section 13.
- Reason / purpose for cross-reference:
- read-across source
- Reason / purpose for cross-reference:
- read-across source
- Species / strain:
- E. coli WP2 uvr A
- Metabolic activation:
- with and without
- Genotoxicity:
- negative
- Cytotoxicity / choice of top concentrations:
- no cytotoxicity nor precipitates, but tested up to recommended limit concentrations
- Vehicle controls validity:
- valid
- Untreated negative controls validity:
- not examined
- True negative controls validity:
- not examined
- Positive controls validity:
- valid
- Species / strain:
- S. typhimurium TA 1535
- Metabolic activation:
- with and without
- Genotoxicity:
- negative
- Cytotoxicity / choice of top concentrations:
- no cytotoxicity nor precipitates, but tested up to recommended limit concentrations
- Remarks:
- 5000 μg/plate
- Vehicle controls validity:
- valid
- Untreated negative controls validity:
- not examined
- True negative controls validity:
- not examined
- Positive controls validity:
- valid
- Species / strain:
- S. typhimurium TA 1537
- Metabolic activation:
- with and without
- Genotoxicity:
- negative
- Cytotoxicity / choice of top concentrations:
- no cytotoxicity nor precipitates, but tested up to recommended limit concentrations
- Vehicle controls validity:
- valid
- Untreated negative controls validity:
- not examined
- True negative controls validity:
- not examined
- Positive controls validity:
- valid
- Species / strain:
- S. typhimurium TA 98
- Metabolic activation:
- with and without
- Genotoxicity:
- negative
- Cytotoxicity / choice of top concentrations:
- no cytotoxicity nor precipitates, but tested up to recommended limit concentrations
- Vehicle controls validity:
- valid
- Untreated negative controls validity:
- not examined
- True negative controls validity:
- not examined
- Positive controls validity:
- valid
- Species / strain:
- S. typhimurium TA 100
- Metabolic activation:
- with and without
- Genotoxicity:
- negative
- Cytotoxicity / choice of top concentrations:
- no cytotoxicity nor precipitates, but tested up to recommended limit concentrations
- Vehicle controls validity:
- valid
- Untreated negative controls validity:
- not examined
- True negative controls validity:
- not examined
- Positive controls validity:
- valid
- Conclusions:
- Interpretation of results:
negative with and without metabolic activation
Under test conditions, no mutagenic effect was observed for the source substances trimethoxy(propyl)silane (CAS: 1067-25-0) and triethoxyoctylsilane (CAS: 2943-75-1) in any of the test strains without and with metabolic activation. As explained in the analogue justification, it is considered that the target and the source substances are unlikely to lead to differences in genetic toxicity potential. - Endpoint:
- in vitro cytogenicity / chromosome aberration study in mammalian cells
- Type of information:
- read-across from supporting substance (structural analogue or surrogate)
- Remarks:
- Summary of available data used for the endpoint assessment of the target substance
- Adequacy of study:
- key study
- Justification for type of information:
- Please refer to the attached justification below and the overall justification for grouping of substances attached in IUCLID Section 13.
- Reason / purpose for cross-reference:
- read-across source
- Reason / purpose for cross-reference:
- read-across source
- Species / strain:
- Chinese hamster Ovary (CHO)
- Metabolic activation:
- with and without
- Genotoxicity:
- negative
- Cytotoxicity / choice of top concentrations:
- no cytotoxicity nor precipitates, but tested up to recommended limit concentrations
- Vehicle controls validity:
- valid
- Untreated negative controls validity:
- valid
- True negative controls validity:
- not examined
- Positive controls validity:
- valid
- Additional information on results:
- A further study on another source substance is available. In a valid study according to OECD 473 and under GLP, trimethoxy(methyl)silane (CAS: 1185-55-3) induced a statistically significant dose related increase in the number of structural aberrations in the presence of activation. It is concluded that trimethoxy(methyl)silane is positive for the induction of chromosome aberrations in the presence of activation under the conditions of the study.
- Conclusions:
- Interpretation of results: negative without metabolic activation, ambigous with metabolic acitivation
Reliable studies from two source substances are available. Triethoxyoctylsilane (2943-75-1) has been tested in a reliable in vitro cytogenetic assay according to OECD TG 473 and under GLP. The test substance did not induce statistically and biologically significant increases in the chromosomal aberration frequency of CHO (Chinese hamster ovary) cells. It is concluded that triethoxyoctylsilane is negative for the induction of chromosome aberrations (not clastogenic) in vitro under the conditions of the test.
In a valid study according to OECD 473 and under GLP, trimethoxy(methyl)silane (CAS: 1185-55-3) induced a statistically significant dose related increase in the number of structural aberrations in the presence of activation. It is concluded that trimethoxy(methyl)silane is positive for the induction of chromosome aberrations in the presence of activation under the conditions of the study.
In conclusion, the induction of chromosome aberrations with metabolic activation is ambigous whereas without metabolic activation it is found to be negative. As explained in the analogue justification, it is considered that the target and the source substances are unlikely to lead to differences in genetic toxicity potential. - Endpoint:
- in vitro gene mutation study in mammalian cells
- Type of information:
- read-across from supporting substance (structural analogue or surrogate)
- Remarks:
- Summary of available data used for the endpoint assessment of the target substance
- Adequacy of study:
- key study
- Justification for type of information:
- Please refer to the attached justification below and the overall justification for grouping of substances attached in IUCLID Section 13.
- Reason / purpose for cross-reference:
- read-across source
- Reason / purpose for cross-reference:
- read-across source
- Species / strain:
- mouse lymphoma L5178Y cells
- Metabolic activation:
- with and without
- Genotoxicity:
- negative
- Cytotoxicity / choice of top concentrations:
- cytotoxicity
- Remarks:
- with S9: growth inhibition starting at 1 mM (I) and 2.0 mM (II), but not dose-dependent; without S9: concentration related increase starting at 1.0 mM (I) and 0.1 mM (II)
- Vehicle controls validity:
- valid
- Untreated negative controls validity:
- not applicable
- True negative controls validity:
- not examined
- Positive controls validity:
- valid
- Additional information on results:
- A further study on another source substance is available.Trimethoxy(methyl)silane (CAS: 1185-55-3) has been tested in a valid study according to OECD 476 and under GLP. A dose-related increase in the mutant frequency was observed in the presence of metabolic activation, and relatively smaller than larger colonies were formed at the two highest concentrations. It is concluded that the substance is positive for mutagenicity to mammalian cells under the conditions of the test.
- Conclusions:
- Interpretation of results: ambigous
Reliable studies from two source substances are available. In a mutagenicity test, conducted according to OECD guideline 476 and GLP, under the test conditions reported, the source substance triethoxyoctylsilane is considered to be non-mutagnic in the in vitro mammalian cell gene mutation assay (thymidine kinase locus) in mouse lymphoma L5178Y cells. The second source substance trimethoxy(methyl)silane (CAS: 1185-55-3) has been tested in a valid study according to OECD 476 and under GLP. A dose-related increase in the mutant frequency was observed in the presence of metabolic activation, and relatively smaller than larger colonies were formed at the two highest concentrations. It is concluded that the substance is positive for mutagenicity to mammalian cells under the conditions of the test.
In conclusion, mammalian mutagenicity is considered ambigous. As explained in the analogue justification, it is considered that the target and the source substances are unlikely to lead to differences in genetic toxicity potential.
Referenceopen allclose all
A second source substance was tested in an Ames test with similar results.
Endpoint conclusion
- Endpoint conclusion:
- adverse effect observed (positive)
Genetic toxicity in vivo
Description of key information
No measured data are available to assess the genotoxic potential of the
registered substance, triethoxypropylsilane, however, reliable data are
available for the following structural analogue substances:
trimethoxymethylsilane (CAS 1185-55-3) and
triethoxy(2,4,4-trimethylpentyl)silane (CAS 35435-21-3).
WoE approach CAS 1185-55-3 and CAS 35435-21-3: In vivo: Mouse
erythrocyte micronucleus assay (oral gavage): negative (according to
OECD TG 474).
Link to relevant study records
- Endpoint:
- in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus
- Type of information:
- read-across from supporting substance (structural analogue or surrogate)
- Remarks:
- Summary of available data used for the endpoint assessment of the target substance
- Adequacy of study:
- key study
- Justification for type of information:
- Please refer to the attached justification below and the overall justification for grouping of substances attached in IUCLID Section 13.
- Reason / purpose for cross-reference:
- read-across source
- Reason / purpose for cross-reference:
- read-across source
- Sex:
- male/female
- Genotoxicity:
- negative
- Toxicity:
- yes
- Remarks:
- clinical signs suggesting systemic toxicity observed
- Vehicle controls validity:
- valid
- Negative controls validity:
- not applicable
- Positive controls validity:
- valid
- Additional information on results:
- A further study on another source substance is available. Triethoxy(2,4,4-trimethylpentyl)silane (CAS: 35435-21-3) has been tested in a reliable in vivo mouse micronucleus assay according to OECD 474 and under GLP. No statistically significant increase in the number of cells with micronuclei was observed after oral administration of the limit dose of 2000 mg/kg bw. Appropriate positive and vehicle controls were included and gave expected results. The PCE / NCE ratio was slightly affected in treated males, indicating that the test item was of low toxicity to the target tissue. It is concluded that the test substance is negative for the induction in micronuclei under the conditions of the test.
- Conclusions:
- Interpretation of results: negative
Reliable studies from two source substances are available. Trimethoxy(methyl)silane (CAS: 1185-55-3) has been tested in a valid study according to OECD 474 and under GLP. No increase in the indicence of micronucleated PCE was observed resulting from exposure to the test substance by oral gavage up to limit concentrations. It is concluded that the test substance is negative for the induction of micronuclei under the conditions of the test. Clinical signs of toxicity were observed that suggested systemic availability, though no toxicity to target tissue was observed. Triethoxy(2,4,4-trimethylpentyl)silane (CAS: 35435-21-3) has been tested in a reliable in vivo mouse micronucleus assay according to OECD 474 and under GLP. No statistically significant increase in the number of cells with micronuclei was observed after oral administration of the limit dose of 2000 mg/kg bw. Appropriate positive and vehicle controls were included and gave expected results. The PCE / NCE ratio was slightly affected in treated males, indicating that the test item was of low toxicity to the target tissue. It is concluded that the test substance is negative for the induction in micronuclei under the conditions of the test.
In conclusion, mammalian mutagenicity is considered negative. As explained in the analogue justification, it is considered that the target and the source substances are unlikely to lead to differences in genetic toxicity potential.
Reference
Endpoint conclusion
- Endpoint conclusion:
- no adverse effect observed (negative)
Additional information
Studies were chosen as key when the available study was of relevance and of sufficient quality for classification and labelling and for risk assessment.
No measured data are available to assess the genetic toxicity potential of the registered substance, triethoxypropylsilane. However, an OECD 471 and an OECD 473 with the registered substance are on-going, but the results will not be available for this current dossier update. Therefore as an interim measure, the hazard assessment was performed based on available data for the structural analogue substances, trimethoxy(propyl)silane (CAS: 1067 -25 -0), triethoxyoctylsilane (CAS: 2943-75-1), trimethoxymethylsilane (CAS: 1185-55-3) and triethoxy(2,4,4-trimethylpentyl)silane (CAS: 35435-21-3). In accordance with Regulation (EC) No. 1907/2006 Annex XI, 1.5 “Grouping of substances and read across” and following the Read across assessment framework (RAAF, ECHA 2017) read across from an analogue substance has been applied to support the human health hazard assessment of tritethoxy(propyl)silane. Details on read across justifications can be found in the attached justification in the respective target entry and in the overall justification for grouping of substances attached in IUCLID Section 13.
Bacterial mutagenicity in vitro:
Key in vitro bacterial reverse mutation studies are available for the structural analogue substances trimethoxypropylsilane and triethoxyoctylsilane in compliance with GLP and according to OECD TG 471 (Huls AG,1996 and Bioservices, 1998). No increase in the frequency of revertants relative to control was observed with or without metabolic activation at any concentration, in any of the test organisms in both studies with the structural analogue substances. The findings of the initial plate incorporation assays were confirmed in the repeat pre-incubation assays in both studies. It is therefore concluded that both structural analogue substances are negative for mutagenicity to bacteria under the conditions of the tests. This therefore supports the lack of bacterial mutagenicity potential of the registered substance, triethoxypropylsilane.
Mammalian Mutagenicity in vitro:
Key in vitro mammalian mutagenicity studies in mouse lymphoma L5178Y cells are availablefor the structural analogue substances trimethoxymethylsilane and triethoxyoctylsilane, respectively, according to OECD 476 and in compliance with GLP. A dose-related increase in the mutant frequency was observed in the presence of metabolic activation, and relatively smaller than larger colonies were formed at the two highest concentrations of trimethoxymethylsilane. It is concluded that trimethoxymethylsilane is positive for mutagenicity to mammalian cells under the conditions of the test (TNO, 2002). With triethoxysilane, no biologically relevant increase in mutation rate was found in mouse lymphoma L5178Y cells with or without metabolic activation in either the initial or the repeat experiment, up to limit and cytotoxic concentrations. The global evaluation factor was not exceeded at any concentration. In addition, colony sizing showed no clastogenic effects in either experiment. It is concluded that triethoxyoctylsilane (CAS: 2943 -75 -1) is negative for mutagenicity to mammalian cells under the conditions of the test (BSL, 2012).
Cytogenicity in vitro:
Key in vitro cytogenicity studies in Chinese hamster ovary (CHO) cells are available for the structural analogue substances trimethoxymethylsilane and triethoxyoctylsilane, respectively, in compliance with GLP and according to OECD TG 474. Trimethoxymethylsilane induced a statistically significant dose related increase in the number of structural aberrations in the presence of metabolic activation. It is concluded that trimethoxymethylsilane is positive for the induction of chromosome aberrations in the presence of metabolic activation under the conditions of the study (Dow, 2004). However, triethoxyoctylsilane did not induce statistically and biologically significant increases in the chromosomal aberration frequency of CHO cells. It is concluded that triethoxyoctylsilane is negative for the induction of chromosome aberrations (not clastogenic) in vitro under the conditions of the test (MA Bioservices 1997).
In vivo:
No measured data are available to assess the in vivo cytogenicity potential of the registered substance, triethoxypropylsilane, however reliable data are available for the structural analogue substances, triethoxy(2,4,4-trimethylpentyl)silane (CAS: 35435-21-3) and trimethoxymethylsilane (CAS: 1185-55-3). Since all three parent substances hydrolyse in contact with water to produce silanol hydrolysis products which are structurally related, read-across between the substances is deemed to be appropriate.
Key in vivo mouse erythrocyte micronucleus studies are available for the structural analogue substances triethoxy(2,4,4-trimethylpentyl)silane and trimethoxymethylsilane conducted according to OECD TG 474 and in compliance with GLP. No statistically significant increase in the number of cells with micronuclei was observed after oral administration of the limit dose of 2000 mg/kg bw with the structural analogue triethoxy(2,4,4-trimethylpentyl)silane (Bioservice 2001). This lack of clastogenic effect was also confirmed with the other structural analogue substance trimethoxy(methyl)silane. No increase in the incidence of micronucleated PCE resulting from exposure up to the limit concentration of 2000 mg/kg bw was observed. Clinical signs of toxicity were evident that suggested systemic availability, though no toxicity to target tissue was observed (RTC, 2002). The results of both studies are in agreement of the lack of cytogenicity potential and thereby supporting the lack of cytogenicity potential of the registered substance, triethoxypropylsilane.
The results of testing in mammalian cells with the structural analogue substance trimethoxymethylsilane showed evidence of genetic toxicity in the presence of metabolic activation. There was evidence for clastogenicity (causing chromosomal aberrations) in the presence of metabolic activation in vitro. An in vivo study did not support this finding, so it is concluded that the in vitro result does not reflect an ability to cause chromosome aberrations in vivo. Clinical signs of toxicity were observed that suggested systemic availability, although it is noted that the test substance did not affect the NCE/PCE ratio. Therefore, with regard to the presented data, the registered substance is assumed to have neither mutagenic nor cytogenic potential.
Justification for classification or non-classification
The available in vitro and in vivo genotoxicity data is reliable and suitable for classification. Based on this data, classification for mutagenicity according to Regulation (EC)1272/2008 is not warranted.
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.
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