Triethoxy(phenyl)silane

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

22 Mar - 30 May 2002

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2002

Report date:

2002

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

no

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Triethoxy(phenyl)silane

EC Number:

212-305-8

EC Name:

Triethoxy(phenyl)silane

Cas Number:

780-69-8

Molecular formula:

C12H20O3Si

IUPAC Name:

triethoxy(phenyl)silane

Details on test material:

- Name of test material (as cited in study report): Silan P-Triethoxy
- Substance type: Colourless liquid
- Physical state: Liquid at room temperature
- Lot/batch No.: GE 03287
- Expiration date of the lot/batch: 2004-01-01
- Storage condition of test material: At room temperature, no direct sun light

Method

Target gene:

his operon

Species / strain

Species / strain 1

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98 and TA 100

Species / strain 2

Species / strain / cell type:

S. typhimurium TA 102

Metabolic activation:

with and without

Metabolic activation system:

cofactor supplemented post-mitochondrial fraction (S9 mix), prepared from the livers of rats treated with Aroclor 1254

Test concentrations with justification for top dose:

See table 1

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: abs. ethanol
- Justification for choice of solvent/vehicle: Solvent chosen due to solubility properties and relative nontoxicity to bacteria.

Controls

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: Sodium azide (TA 1535, TA 100); 2-nitrofluorene (TA 98); 9-aminoacridine (TA 1537); ethyl methanesulphonate (TA 102); +S9: 2-anthracene amide (TA 98, TA 102, TA 1537); cyclophosphamide (TA 100, TA 1535)

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar (plate incorporation); preincubation

DURATION
- Preincubation period: 60 minutes
- Exposure duration: 48 hours

NUMBER OF REPLICATIONS: 3 plates for each test concentration

DETERMINATION OF CYTOTOXICITY
- Method: relative total growth

POSITIVE CONTROLS
Plate incorporation
-S9: Sodium azide (TA 1535: 770.3 µg/plate, TA 100: 1142.3 µg/plate); 2-nitrofluorene (TA 98: 648.3 µg/plate); 9-aminoacridine (TA 1537: 527 µg/plate); ethyl methanesulphonate (TA 102: 1171 µg/plate); +S9: 2-anthracene amide (TA 98: 618.7 µg/plate, TA 102: 1200 µg/plate, TA 1537: 557.7 µg/plate); cyclophosphamide (TA 100: 1094.7 µg/plate, TA 1535:728.7 µg/plate)

Preincubation
-S9: Sodium azide (TA 1535: 808.3 µg/plate, TA 100: 1145 µg/plate); 2-nitrofluorene (TA 98: 618.7 µg/plate); 9-aminoacridine (TA 1537: 653.3 µg/plate); methyl methanesulphonate (TA 102: 789.3 µg/plate); +S9: 2-anthracene amide (TA 98: 731.7 µg/plate, TA 102: 1125.3 µg/plate, TA 1537: 793.3 µg/plate); cyclophosphamide (TA 100: 1133 µg/plate, TA 1535: 891 µg/plate)

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 98, TA 100 and TA 102 and 3-fold of the solvent control for TA 1535 and TA 1537 in both independant experiments. Positive results have to be reproducible and the histidine independence of the revertants has to be confirmed by streaking random samples on histidine-free agar plates.

Statistics:

MANN and WHITNEY and Spearman's rank correlation.

Results and discussion

Test results

Test results 1

Species / strain:

S. typhimurium TA 102

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

Scarce background lawn from 100 µg. >50% reduction in revertants from 316 µg.

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Test results 2

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

Scarce background lawn from 100 µg. >50% reduction in revertants from 316 µg.

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Test results 3

Species / strain:

S. typhimurium TA 1537

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

Scarce background lawn from 100 µg. >50% reduction in revertants from 316 µg.

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Test results 4

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

Scarce background lawn from 100 µg. >50% reduction in revertants from 316 µg.

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Test results 5

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

Scarce background lawn from 100 µg. >50% reduction in revertants from 316 µg.

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Additional information on results:

See tables 1-4

COMPARISON WITH HISTORICAL CONTROL DATA: Controls were within range of historical data.

Any other information on results incl. tables

Table 2: Dose range-finding study Number of revertants per plate (2 plates)

	TA100
Conc. (µg/plate)	Plate 1	Plate 2	Cytotoxic (yes/no)
0*	118	122	No
0.316	108	136	No
1	112	129	No
3.16	127	100	No
10	108	113	No
31.6	120	112	No
100#	135	216	Yes
316#	105	0	Yes
1000#	149	139	Yes
3160	0	0	Yes
5000	0	0	Yes

*solvent control with Abs. ethanol

#colonies may represent pinpoint colonies rather than revertants

Table 3: Experiment 1 Plate incorporation Number of revertants per plate (mean of 3 plates)

	TA98			TA100			TA102
Conc. (µg/plate)	— MA	+ MA	Cytotoxic (yes/no)	— MA	+ MA	Cytotoxic (yes/no)	— MA	+ MA	Cytotoxic (yes/no)
0*	34	40.7	No	126	121.7	No	258	268.3	No
3.16	29	36	No	119.7	123.7	No	238.3	307.7	No
10	31.3	41.7	No	119.7	112.3	No	252.7	290.3	No
31.6	30.7	38.3	No	133.3	113.3	No	255.3	282.3	No
100	30	32.7	No	110	109.3	No	254.3	269.7	No
316	33.7	37.7	No	127.7	127.3	Yes	254.7	304	No
Positive control	618.7	618.7	No	1142.3	1094.7	No	789.3	1200	No

*solvent control with Abs. ethanol

Table 3: Experiment 1 Plate incorporation Number of revertants per plate (mean of 3 plates)

	TA1535			TA1537
Conc. (µg/plate)	— MA	+ MA	Cytotoxic (yes/no)	— MA	+ MA	Cytotoxic (yes/no)
0*	15.7	15.3	No	10.7	10.3	No
3.16	18.7	11.3	No	6.7	9	No
10	17.7	15.3	No	7	11.7	No
31.6	16	16	No	8.3	10.3	No
100	15.7	21.7	No	7.7	10	No
316	12.7	12.7	Yes	9.7	11.3	Yes
Positive control	808.3	728.7	No	527	557.7	No

*solvent control with Abs. ethanol

Table 4: Experiment 2 Preincubation Number of revertants per plate (mean of 3 plates)

	TA98			TA100			TA102
Conc. (µg/plate)	— MA	+ MA	Cytotoxic (yes/no)	— MA	+ MA	Cytotoxic (yes/no)	— MA	+ MA	Cytotoxic (yes/no)
0*	28.7	36	No	122.7	131	No	268	251.3	No
3.16	31	34	No	123.3	128	No	259.7	277.3	No
10	27.7	28.3	No	122	134.7	No	247.7	248	No
31.6	26.3	39	No	121	136.7	No	247.3	317.7	No
100	25	0	Yes	145.3	139.3	Yes	207.3	277.3	Yes
316	26	0	Yes	0	0	Yes	258	253.7	Yes
Positive control	648.3	731.7	No	1145	1133	No	1171	1125.3	No

*solvent control with Abs. ethanol

Table 4: Experiment 2 Preincubation Number of revertants per plate (mean of 3 plates)

	TA1535			TA1537
Conc. (µg/plate)	— MA	+ MA	Cytotoxic (yes/no)	— MA	+ MA	Cytotoxic (yes/no)
0*	15	14.3	No	11.7	13	No
3.16	11.3	13.7	No	12	12.3	No
10	12	12	No	16.7	12.7	No
31.6	9.7	14.7	No	11	14.3	No
100	0	0	Yes	0	0	Yes
316	0	0	Yes	0	0	Yes
Positive control	770.3	891	No	653.3	793.3	No

*solvent control with Abs. ethanol

Applicant's summary and conclusion

Conclusions:

Interpretation of results: negative

Pronounced cytotoxicity (scarce background lawn) was noted at the concentrations of 100 µg up to 5000 µg of the test substance. Reduction of the number of revertants by more than 50% was noted at concentrations of 316, 3160 and 5000 µg of the test substance.

In a highly reliable test, conducted in accordance with OECD 471, under GLP, no mutagenic effect was observed for the test substance in any of the 5 test strains in two independent experiments without and with metabolic activation (plate incorporation or preincubation test). The test substance is not mutagenic in the test strains used.