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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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: 201-127-6 | CAS number: 78-62-6
- 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
Endpoint summary
Administrative data
Key value for chemical safety assessment
Genetic toxicity in vitro
Description of key information
Gene mutation (Bacterial reverse mutation assay / Ames test): S.
typhimurium TA 98, TA 100, TA 1535, TA 1537, TA 1538, E. coli
W3110/polA+, E. coli P3478/polA- and Saccharomyces cerevisiae: negative
with and without metabolic activation (OECD 471)
Mammalian cytogenicity (Chromosome Aberration): negative with and
without metabolic activation (OECD 473)
Mammalian mutagenicity (mouse lymphoma assay): negative with and without
metabolic activation (OECD 476)
Link to relevant study records
- Endpoint:
- in vitro gene mutation study in bacteria
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Study period:
- 1977 - 1978
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- comparable to guideline study with acceptable restrictions
- Remarks:
- The study was conducted according to a Litton Bionetics Inc. method but full details are not available
- Qualifier:
- equivalent or similar to guideline
- Guideline:
- OECD Guideline 471 (Bacterial Reverse Mutation Assay)
- Deviations:
- yes
- Remarks:
- no analytical purity stated; only single cultures tested, tester strains TA 102 or E. coli WP2 were not used in the study as required in the appropriate OECD test guideline
- GLP compliance:
- no
- Type of assay:
- bacterial reverse mutation assay
- Target gene:
- his operon
- Species / strain / cell type:
- S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
- Species / strain / cell type:
- S. typhimurium TA 1538
- Species / strain / cell type:
- E. coli, other: W3110/polA+
- Species / strain / cell type:
- E. coli, other: P3478/polA-
- Species / strain / cell type:
- yeast, other: Saccharomyces cerevisiae (D4)
- Metabolic activation:
- with and without
- Metabolic activation system:
- Aroclor 1254-induced rat liver S9-mix
- Test concentrations with justification for top dose:
- Main experiment:
- 0.001, 0.01, 0.1, 1, 5 µL/plate (with and without metabolic activation) - Vehicle / solvent:
- - Vehicle(s)/solvent(s) used: DMSO
- Justification for choice of solvent/vehicle: Solubility properties and relative non-toxicity to bacteria - Untreated negative controls:
- no
- Negative solvent / vehicle controls:
- yes
- True negative controls:
- no
- Positive controls:
- yes
- Positive control substance:
- other: -S9-mix: MNNG: 10 µg/plate (TA 1535, TA 100, D4), QM: 10 µg/plate (TA 1537), NF: 100 µg/plate (TA 1538, TA 98); +S9-mix: ANTH: 100 µg/plate (TA 1535, TA 100), AMQ: 100 µg/plate (TA 1537), AAF: 100 µg/plate (TA 1538, TA 98), DMNA: 100 µM/plate (D4)
- Details on test system and experimental conditions:
- METHOD OF APPLICATION: in agar (plate incorporation)
DURATION
- Expression time (cells in growth medium): 48 h (Ames test), 24 h (DNA repair test)
NUMBER OF REPLICATIONS: single culture/test concentration
DETERMINATION OF CYTOTOXICITY
- Method: relative total growth
- Evaluation criteria:
- A result is positive if the number of revertants is significantly increased compared with the solvent control to at least 2-fold of the solvent control for TA 100, TA 1535, TA 1537 and TA 1538, and 2-3 times the solvent control for TA 98 and D4.
- Species / strain:
- S. typhimurium, other: TA 1535, TA1537, TA98, and TA100
- 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 applicable
- Positive controls validity:
- valid
- Species / strain:
- S. typhimurium TA 1538
- Metabolic activation:
- with and without
- Genotoxicity:
- negative
- Cytotoxicity / choice of top concentrations:
- cytotoxicity
- Remarks:
- ≥1 µl/plate -S9-mix
- Vehicle controls validity:
- valid
- Untreated negative controls validity:
- not applicable
- Positive controls validity:
- valid
- Species / strain:
- yeast, other: Saccharomyces cerevisiae (D4)
- 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 applicable
- Positive controls validity:
- valid
- Species / strain:
- E. coli, other: W3110/po1A+
- 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 applicable
- Positive controls validity:
- valid
- Species / strain:
- E. coli, other: P3478/po1A-
- 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 applicable
- Positive controls validity:
- valid
- Additional information on results:
- ADDITIONAL INFORMATION ON CYTOTOXICITY:
Marked cytotoxicity was observed in tester strain TA 1538 in the absence of metabolic activation at concentration ≥1 µl/plate. No relevant cytotoxicity was observed for the other tester strains at any concentration either in the presence or in the absence of metabolic activation. - Conclusions:
- No mutagenic effect was observed for the test substance tested up to cytotoxic concentration in any of the test strains in two independent experiments without and with metabolic activation. The test substance is non-mutagenic in test strains used.
- Endpoint:
- in vitro cytogenicity / chromosome aberration study in mammalian cells
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Study period:
- 1977 - 1978
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- comparable to guideline study with acceptable restrictions
- Qualifier:
- equivalent or similar to guideline
- Guideline:
- OECD Guideline 473 (In Vitro Mammalian Chromosome Aberration Test)
- Deviations:
- yes
- Remarks:
- only 50 cells scored - guideline requires 200. no duplicates. Number cells with 2 or more aberrations presented (rather than % with aberrations
- GLP compliance:
- no
- Type of assay:
- other: in vitro mammalian chromosome aberration test (migrated information)
- Target gene:
- Not applicable
- Species / strain / cell type:
- mouse lymphoma L5178Y cells
- Metabolic activation:
- with and without
- Metabolic activation system:
- mouse liver S9-mix
- Test concentrations with justification for top dose:
- Main experiment:
- 0.1, 0.2, 0.4, 0.8, 1.2, 1.6, 2.4, 3.2, 4.8 µLl/mL(without metabolic activation)
- 0.1, 0.2, 0.4, 0.8, 1.2, 1.6, 2.4, 3.2 µL/mL (with metabolic activation) - Vehicle / solvent:
- - Vehicle(s)/solvent(s) used: ethanol
- Justification for choice of solvent/vehicle: It is assumed by the reviewer that solvent was chosen based on solubility properties and relative non toxicity to mouse lymphoma cells. - Untreated negative controls:
- yes
- Negative solvent / vehicle controls:
- yes
- True negative controls:
- no
- Positive controls:
- yes
- Positive control substance:
- N-dimethylnitrosamine
- ethylmethanesulphonate
- Details on test system and experimental conditions:
- METHOD OF APPLICATION: in medium
DURATION
- Exposure duration: 4 and 24 h
- Fixation time (start of exposure up to fixation or harvest of cells): 4 h treatment: 24 h; 24 h treatment: 24 h
STAIN: Giesma
NUMBER OF REPLICATIONS: single cultures/test concentration
NUMBER OF CELLS EVALUATED: 50 cells per concentration
DETERMINATION OF CYTOTOXICITY
- Method: mitotic index
- Statistics:
- The average numbers of chromosome aberrations per cell was calculated and compared with values for the negative control compound to determine significance (Students t-test (p<0.05 and p<0.01)).
- Species / strain:
- mouse lymphoma L5178Y cells
- Metabolic activation:
- with and without
- Genotoxicity:
- negative
- Cytotoxicity / choice of top concentrations:
- cytotoxicity
- Remarks:
- 4.8 µL/mL -S9-mix
- Vehicle controls validity:
- valid
- Untreated negative controls validity:
- valid
- Positive controls validity:
- valid
- Additional information on results:
- ADDITIONAL INFORMATION ON CYTOTOXICITY:
- Cytotoxicity was only recorded at a concentration of 4.8 µL/plate in the absence of metabolic activation. - Conclusions:
- Under test conditions, there was some evidence for increased levels of chromosome aberrations, but the levels of increase were minimal. No properly stained spreads were used for the tests. The test substance is considered non clastogenic in mouse lymphoma cells.
- Endpoint:
- in vitro gene mutation study in mammalian cells
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Study period:
- 1977 - 1978
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- comparable to guideline study with acceptable restrictions
- Qualifier:
- equivalent or similar to guideline
- Guideline:
- OECD Guideline 476 (In Vitro Mammalian Cell Gene Mutation Test)
- Deviations:
- no
- GLP compliance:
- no
- Type of assay:
- other: in vitro mammalian cell gene mutation tests using the thymidine kinase gene (migrated information)
- Target gene:
- TK locus
- Species / strain / cell type:
- mouse lymphoma L5178Y cells
- Metabolic activation:
- with and without
- Metabolic activation system:
- mouse liver S9-mix
- Test concentrations with justification for top dose:
- Experiment I:
- 0.1, 0.2, 0.4, 0.8, 1.6 µL/mL (without metabolic activation)
- 0.2, 0.4, 0.8, 1.6, 3.2 µL/mL (with metabolic activation)
Experiment II:
- 1.6, 2.4, 3.2, 4.8 µL/mL (with and without metabolic activation) - Vehicle / solvent:
- - Vehicle(s)/solvent(s) used: ethanol
- Untreated negative controls:
- no
- Negative solvent / vehicle controls:
- yes
- True negative controls:
- no
- Positive controls:
- yes
- Positive control substance:
- N-dimethylnitrosamine
- ethylmethanesulphonate
- Details on test system and experimental conditions:
- METHOD OF APPLICATION: in medium
DURATION
- Exposure duration: 4 h
- Expression time (cells in growth medium): 3 days
- Selection time: 10 days
- Fixation time (start of exposure up to fixation or harvest of cells): 13 days
NUMBER OF REPLICATIONS: two independent experiments with single cultures/test concentration each
DETERMINATION OF CYTOTOXICITY
- Method: cloning efficiency; relative total growth - Evaluation criteria:
- A compound is considered mutagenic in the mouse lymphoma assay if a dose response relationship is observed over three of the four dose levels employed; the minimum increase at the high level of the dose response curve is at least 2.5 times greater than the solvent control value; the solvent control data are within the normal range of the spontaneous background of the TK locus.
- Species / strain:
- mouse lymphoma L5178Y cells
- Metabolic activation:
- with and without
- Genotoxicity:
- negative
- Cytotoxicity / choice of top concentrations:
- cytotoxicity
- Remarks:
- 0.4 and 3.2 µL/mL with S9-mix
- Vehicle controls validity:
- valid
- Untreated negative controls validity:
- not applicable
- Positive controls validity:
- valid
- Additional information on results:
- ADDITIONAL INFORMATION ON CYTOTOXICITY:
- Evident toxicity was only recorded at concentrations of 0.4 and 3.2 µg/mL in the presence of metabolic activation. - Conclusions:
- The substance was tested in an in vitro mutagenicity assay in mouse lymphoma L5178Y cells. The test substance is non-mutagenic in mouse lymphoma cells under the conditions of the test.
Referenceopen allclose all
Table 1: Experiment 1 Plate incorporation Number of revertants per plate
|
TA98 |
TA100 |
TA1535 |
||||||
Conc. |
— MA |
+ MA |
Cytotoxic |
— MA |
+ MA |
Cytotoxic |
— MA |
+ MA |
Cytotoxic |
0* |
36 |
44 |
No |
92 |
134 |
No |
28 |
14 |
No |
0.001 |
30 |
55 |
No |
76 |
117 |
No |
17 |
18 |
No |
0.01 |
26 |
52 |
No |
88 |
155 |
No |
16 |
21 |
No |
0.1 |
25 |
43 |
No |
81 |
142 |
No |
15 |
15 |
No |
1 |
34 |
53 |
No |
84 |
126 |
No |
16 |
13 |
No |
5 |
26 |
58 |
No |
75 |
125 |
No |
12 |
12 |
No |
Positive control |
>1000 |
>1000 |
No |
610 |
811 |
No |
>1000 |
299 |
No |
*solvent control with DMSO
Table 2: Experiment 1 Plate incorporation Number of revertants per plate
|
TA 1537 |
TA 1538 |
D4 |
||||||
Conc. |
— MA |
+ MA |
Cytotoxic |
— MA |
+ MA |
Cytotoxic |
— MA |
+ MA |
Cytotoxic |
0* |
14 |
15 |
No |
28 |
31 |
No |
44 |
154 |
No |
0.001 |
30 |
14 |
No |
15 |
31 |
No |
48 |
222 |
No |
0.01 |
19 |
26 |
No |
26 |
31 |
No |
42 |
64 |
No |
0.1 |
22 |
19 |
No |
23 |
29 |
No |
46 |
202 |
No |
1 |
14 |
18 |
No |
14 |
30 |
No |
43 |
234 |
No |
5 |
10 |
13 |
No |
15 |
35 |
No |
50 |
228 |
No |
Positive control |
>1000 |
392 |
No |
701 |
>1000 |
No |
746 |
242 |
No |
*solvent control with DMSO
Table 1: Summary of chromosome aberrations
Test item |
Concentration in µl/ml |
Mitotix index (%) |
Aberrant cells (%) |
Exposure period 4 h, fixation time 24 h, without S9-mix |
|||
Negative control |
- |
8.8 |
3.3 |
Solvent control |
- |
8.5 |
1.7 |
Positive control |
0.5 |
5.8 |
14.3 |
Test substance |
0.1 |
8.3 |
0.0 |
0.2 |
11.3 |
4.0 |
|
0.4 |
10.2 |
2.0 |
|
0.8 |
4.2 |
0.0 |
|
1.2 |
10.6 |
4.0 |
|
1.6 |
9.6 |
6.0 |
|
2.4 |
6.6 |
0.0 |
|
3.2 |
7.2 |
2.0 |
|
4.8 |
- |
- |
|
Exposure period 4 h, fixation time 24 h, with S9-mix |
|||
Negative control |
- |
8.9 |
2.8 |
Solvent control |
- |
8.0 |
1.1 |
Positive control |
0.3 |
5.4 |
14.8 |
Test substance |
0.1 |
9.6 |
0.0 |
0.2 |
10.8 |
0.0 |
|
0.4 |
11.4 |
0.0 |
|
0.8 |
9.7 |
0.0 |
|
1.2 |
6.0 |
2.0 |
|
1.6 |
10.0 |
4.0 |
|
2.4 |
8.3 |
6.0 |
|
3.2 |
8.1 |
2.0 |
Table 1: Summary of mutagenicity assay (experiment I)
Test item |
Dose level (µl/ml) |
Relative suspension growth (% of control) |
Total mutant clones |
Total viable clones |
Relative cloning efficiency (% of control) |
Percent relative growth* |
Mutant frequency (x 10^-6)** |
Exposure period 4 h, without S9-mix |
|||||||
Solvent control |
- |
100.0 |
9.0 |
216.0 |
100.0 |
100.0 |
4.2 |
Negative control |
- |
120.3 |
13.0 |
208.0 |
96.3 |
115.8 |
6.3 |
Positive control |
5 |
44.1 |
276.0 |
82.0 |
38.0 |
16.8 |
336.6 |
Test substance |
0.1 |
39.2 |
30.0 |
182.0 |
84.3 |
33.1 |
16.5 |
0.2 |
46.2 |
23.0 |
174.0 |
80.6 |
37.2 |
13.2 |
|
0.4 |
60.3 |
18.0 |
175.0 |
81.0 |
48.9 |
10.3 |
|
0.8 |
62.9 |
20.0 |
229.0 |
106.0 |
66.7 |
8.7 |
|
1.6 |
39.0 |
36.0 |
182.0 |
84.3 |
33.5 |
19.8 |
|
Exposure period 4 h, with S9-mix |
|||||||
Solvent control |
- |
100.0 |
24.5 |
252.0 |
100.0 |
100.0 |
9.7 |
Negative control |
- |
112.0 |
24.0 |
151.0 |
59.9 |
67.1 |
15.9 |
Positive control |
5 |
25.6 |
117.0 |
39.0 |
15.5 |
4.0 |
300.0 |
Test substance |
0.2 |
81.3 |
33.0 |
200.0 |
79.4 |
64.5 |
16.5 |
0.4 |
135.7 |
30.0 |
133.0 |
52.8 |
71.6 |
22.6 |
|
0.8 |
92.2 |
41.0 |
172.0 |
68.3 |
62.9 |
23.8 |
|
1.6 |
76.7 |
44.0 |
152.0 |
60.3 |
46.2 |
28.9 |
|
3.2 |
15.9 |
27.0 |
188.0 |
74.6 |
11.8 |
14.4 |
* = Relative (Suspension Growth x Relative Cloning Efficiency) / 100
** = (Mutant Clones / Viable Clones) x 10^-4
Table 2: Summary of mutagenicity assay (experiment II)
Test item |
Dose level (µl/ml) |
Relative suspension growth (% of control) |
Total mutant clones |
Total viable clones |
Relative cloning efficiency (% of control) |
Percent relative growth |
Mutant frequency (x 10^6) |
Exposure period 4 h, without S9-mix |
|||||||
Solvent control |
- |
100.0 |
48.0 |
370.0 |
100.0 |
100.0 |
13.0 |
Negative control |
- |
136.2 |
34.0 |
325.0 |
87.8 |
119.7 |
10.5 |
Positive control |
5 |
50.2 |
778.0 |
133.0 |
35.9 |
18.0 |
585.0 |
Test substance |
1.6 |
106.2 |
52.0 |
250.0 |
67.6 |
71.8 |
20.8 |
2.4 |
83.8 |
18.0 |
308.0 |
83.2 |
69.7 |
5.8 |
|
3.2 |
59.5 |
57.0 |
303.0 |
81.9 |
48.7 |
18.8 |
|
4.8 |
24.9 |
50.0 |
270.0 |
73.0 |
18.2 |
18.5 |
|
Exposure period 4 h, with S9-mix |
|||||||
Solvent control |
- |
100.0 |
80.0 |
384.0 |
100.0 |
100.0 |
20.0 |
Negative control |
- |
205.1 |
45.0 |
299.0 |
77.9 |
159.7 |
15.1 |
Positive control |
5 |
71.1 |
376.0 |
132.0 |
34.4 |
24.4 |
284.8 |
Test substance |
1.6 |
128.0 |
60.0 |
309.0 |
80.5 |
103.0 |
19.4 |
2.4 |
104.1 |
68.0 |
375.0 |
97.7 |
101.6 |
18.1 |
|
3.2 |
159.5 |
55.0 |
208.0 |
54.2 |
86.4 |
26.4 |
|
4.8 |
35.3 |
72.0 |
267.0 |
69.5 |
24.5 |
27.0 |
* = Relative (Suspension Growth x Relative Cloning Efficiency) / 100
** = (Mutant Clones / Viable Clones) x 10^-4
Endpoint conclusion
- Endpoint conclusion:
- no adverse effect observed (negative)
Genetic toxicity in vivo
Endpoint conclusion
- Endpoint conclusion:
- no study available
Additional information
Genetic toxicity (mutagenicity) in bacteria in vitro
A reliable bacterial gene mutation study (Ames test) performed equivalent or similar to OECD TG 471 with Diethoxy(dimethyl)silane (CAS 78-62-6) is available (SEHSC, 1978). The strains Salmonella typhimurium TA 1535, TA 1537, TA 1538, TA 98, TA 100, E. coli W3110/polA+, E. coli P3478/polA- and Saccharomyces cerevisiae were tested according to the plate incorporation procedure in the absence and presence of a metabolic activation system (Aroclor 1254-induced rat liver S9-mix). The experiment was conducted with single cultures at concentrations from 0.001, 0.01, 0.1, 1, and 5 µL/plate. Marked cytotoxicity was observed in tester strain TA 1538 in the absence of metabolic activation at concentration ≥1 µL/plate. No relevant cytotoxicity was observed for the other tester strains at any concentration either in the presence or in the absence of metabolic activation. Appropriate solvent (DMSO) and positive controls were included and gave the expected results. No significant increase in the number of revertants was observed in any of the tester strains TA 98, TA 100, TA 1535, TA 1537, TA 1538 and Saccharomyces cerevisiae with and without metabolic activation. In addition, no zones of inhibition were recorded for the tester trains E. coli W3110/polA+ and E. coli P3478/polA- in the presence or absence of metabolic activation in the DNA repair test. Taken together and based on the results of the study, the test material was considered to be non-mutagenic under the conditions of the test.
Genetic toxicity (cytogenicity) in mammalian cells in vitro
An in vitro chromosome aberration test in mouse lymphoma L5178Y cells was performed with Diethoxy(dimethyl)silane (CAS 78-62-6) equivalent or similar to OECD TG 473 (SCHSC, 1978). Mouse lymphoma cells were treated with Diethoxy(dimethyl)silane or vehicle (ethanol) in the absence or presence of a metabolic activation system (non-induced mice liver S9-mix) at concentrations of 0.1, 0.2, 0.4, 0.8, 1.2, 1.6, 2.4, 3.2, 4.8 µL/mL (without metabolic activation) and 0.1, 0.2, 0.4, 0.8, 1.2, 1.6, 2.4, 3.2 µL/mL (with metabolic activation) for 4 h. After the 4 h exposure period with the test material cells were incubated with BUdR for additional 20 h and fixed and stained with Giemsa and either analysed for chromosome aberrations or sister chromatid exchanges (SCE). Appropriate negative, solvent and positive controls were included in the test and gave the expected results. Cytotoxicity was only recorded at a concentration of 4.8 µL/plate in the absence of metabolic activation. However, only single cultures for each test concentration were performed and only 50 cells per concentration were evaluated which is a deviation of the current OECD TG. Evaluation of sister chromatid exchanges revealed no statistically significant, dose-related increase of SCEs in the absence of metabolic activation. In contrast, a statistically significant, dose-related increase of SCEs was observed in the presence of metabolic activation. Nevertheless, since only single cultures were performed and only 10 cells were evaluated for SCEs for each test concentration, the statistically significant increase of SCEs in the presence of metabolic activation is considered not to be reliable. Taken together and based on the results of the chromosome aberration test the test substance did not cause a statistically significant, dose-related increase in chromosome aberrations and is therefore considered to be non-clastogenic in mouse lymphoma L5178Y cells under the tested conditions.
Genetic toxicity (mutagenicity) in mammalian cells in vitro
An in vitro Mammalian Cell Gene Mutation Test was performed with Diethoxy(dimethyl)silane (CAS 78-62-6) in mouse lymphoma L5178Y cells (heterozygous at the thymidine kinase locus) equivalent or similar to OECD TG 476 (SCHSC, 1978). Mouse lymphoma cells were treated with Diethoxy(dimethyl)silane or vehicle (ethanol) in two independent experiments in the absence or presence of a metabolic activation system (non-induced mice liver S9-mix) at concentrations of 0.1, 0.2, 0.4, 0.8, 1.6, 2.4, 3.2, 4.8 µL/mL (without metabolic activation, experiment I) and 0.2, 0.4, 0.8, 1.6, 2.4, 3.2, 4.8 µL/mL (with metabolic activation, experiment I) and 1.6, 2.4, 3.2 and 4.8 µL/mL (with and without metabolic activation, experiment II) for 4 h. After the 4 h exposure period with the test material mouse lymphoma cells were cultured in growth medium for 3 days followed by incubation in selective medium for additional 10 days. Fixation of the cells was performed 13 days after start of exposure with the test material. Evident toxicity was only recorded at concentrations of 0.4 and 3.2 µg/mL in the presence of metabolic activation. The vehicle controls had acceptable mutant frequency values that were within the normal range for the L5l78Y cell line at the TK locus. The positive control materials induced marked increases in the mutant frequency indicating the satisfactory performance of the test and of the activity of the metabolising system. The test substance did not cause a statistically significant, dose-related increase in mutant frequency either in the absence or in the presence of metabolic activation. Therefore, the test substance is considered not to be mutagenic in the mouse lymphoma L5178Y test system under the conditions of the test.
A further gene mutation test as part of the previously described in vitro Mammalian Cell Gene Mutation Test was performed with Diethoxy(dimethyl)silane (CAS 78-62-6) investigating the primary DNA damage in mouse lymphoma L5178Y cells (heterozygous at the thymidine kinase locus) (SCHSC, 1978). Prior to treatment, mouse lymphoma L5178Y cells were exposed to 0.5 µCi/mL 14C-thymidine for at least 20 h to label the cellular DNA followed by further incubation with non-radiolabeled medium for 24 h. Duplicate cultures are exposed to Diethoxy(dimethyl)silane at concentrations of 0.6, 1.2 and 2.4 µL/mL for 4 or 2 h in the absence or presence of metabolic activation, respectively followed by primary DNA damage evaluation via alkaline elution. No marked toxicity was recorded at any test material concentration either in the presence or absence of metabolic activation. Appropriate solvent (ethanol) and positive controls were included and gave the expected results. The test material did not induce a statistically significant, dose-related response in the alkaline elution assay either in the presence or absence of metabolic concentration. Therefore, the test substance is considered not to induce primary DNA damage in the mouse lymphoma L5178Y test system under the conditions of the test.
Based on the available data on in vitro genetic toxicity with Diethoxy(dimethyl)silane (CAS 78-62-6) sufficient evidence is available to conclude that the registration is neither mutagenic in bacterial and mammalian cells nor clastogenic in mammalian cells.
Justification for classification or non-classification
The available data on genetic toxicity of Diethoxy(dimethyl)silane do not meet the criteria for classification according to Regulation (EC) No 1272/2008, and are therefore conclusive but not sufficient for classification.
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.