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Toxicological information

Genetic toxicity: in vitro

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Administrative data

Endpoint:
in vitro gene mutation study in bacteria
Remarks:
Type of genotoxicity: gene mutation
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1999-07-09 to 1999-10-16
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: The study was conducted according to the appropriate OECD test guideline, and in compliance with GLP.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1999
Report Date:
1999

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
GLP compliance:
yes
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent

Method

Species / strainopen allclose all
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Species / strain / cell type:
E. coli WP2 uvr A
Metabolic activation:
with and without
Metabolic activation system:
Aroclor induced rat liver S9
Test concentrations with justification for top dose:
100, 333, 1000, 3333, and 5000 µg/plate
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: DMSO
- Justification for choice of solvent/vehicle: Stability in solvent
Controlsopen allclose all
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: 2-aminoanthracene
Remarks:
all strains with activation
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
sodium azide
Remarks:
TA 100 and TA 1535 without activation
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
9-aminoacridine
Remarks:
TA 1537 without activation
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
methylmethanesulfonate
Remarks:
E. coli WP2 uvrA without activation
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
2-nitrofluorene
Remarks:
TA 98 without activation
Details on test system and experimental conditions:
METABOLIC ACTIVATION
0.5 ml of S9 mix containing 10% Aroclor induced rat liver S9 with NADP as cofactor. The S9 was assayed for ability to metabolize 2-aminoanthracene and 7,12-dimethylbenz(a)anthracene to forms mutagenic to S. typhimurium TA100

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

DURATION
- Preincubation period: 60 minutes
- Exposure duration: 48-72 hours
- Expression time (cells in growth medium):48-72 hours
- Fixation time (start of exposure up to fixation or harvest of cells): 48-72 hours

SELECTION AGENT (mutation assays):

NUMBER OF REPLICATIONS: concentrations were plated in triplicate, experiment was repeated

NUMBER OF CELLS EVALUATED: 0.3 x 10E09 cells per ml

DETERMINATION OF CYTOTOXICITY
- Method: ; other: condition of bacterial lawn

OTHER EXAMINATIONS:
- Determination of polyploidy:
- Determination of endoreplication:
- Other:

OTHER:The study was performed in two phases, using the preincubation and plate incorporation methodology.  The first phase, the preliminary toxicity study, was used to establish the dose range for the mutagenicity assay.  The second phase, the mutagenicity assay (initial and independent repeat assays), was used to evaluate the mutagenic potential of the test article.
Evaluation criteria:
A substance is considered positive if it causes a dose-related increase in the mean revertants per plate of at least one tester strain with a minimum of two increasing concnetrations of test substance, of greater than two times (TA 98, 100 and E. coli) or 3 times (TA 1535 and 1537) the vehicle control value.
Statistics:
No statistical evaluation carried out.

Results and discussion

Test results
Species / strain:
other: S. typhimurium strains TA 98, TA 100, TA 1535, TA 1537; E. coli strain WP2uvrA
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
other: no appreciable toxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
not applicable
Positive controls validity:
valid
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Any other information on results incl. tables

Preliminary Toxicity Test: Ten dose levels, ranging from 6.7 to 5000 ug/plate were tested with the four Salmonella strains and WP2 uvrA in the presence or absence of S9.  Neither precipitate nor appreciable toxicity was observed. 

No positive responses were observed in the mutagenicity assays. Neither precipitate nor appreciable
toxicity was observed.  All bacterial strains exhibited mutagenic responses to the positive control substances,
indicating that the tests were sensitive and valid.

Table 1: Preincubation experiment 1: Number of revertants per plate (mean of 3 plates)  

Concentration

µg/plate

Strain    TA 98

Strain    TA 100

Strain    TA 1535

Strain    TA 1537

E. coli WP2 uvrA

- MA

+ MA

- MA

+ MA

- MA

+ MA

- MA

+ MA

- MA

+ MA

0*

16

21

137

134

10

9

8

8

12

17

100

12

18

146

122

11

14

5

6

15

16

333

11

16

141

154

9

10

7

7

15

15

1000

13

17

141

161

9

8

6

6

16

15

3333

12

11

134

159

12

7

6

6

16

16

5000

12

15

135

147

9

7

7

5

19

17

Positive control

745

416

700

611

420

100

229

78

371

173

* Solvent control with DMSO

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

Concentration

µg/plate

 

Strain    TA 98

Strain    TA 100

Strain    TA 1535

Strain    TA 1537

E. coli WP2 uvrA

- MA

+ MA

- MA

+ MA

- MA

+ MA

- MA

+ MA

- MA

+ MA

0*

14

16

104

131

13

12

9

9

12

15

100

14

15

112

136

10

13

10

9

15

12

333

13

17

127

143

13

12

9

9

16

13

1000

14

16

108

147

13

11

6

8

13

14

3333

11

14

111

123

11

12

6

9

15

14

5000

12

17

109

153

13

13

5

7

12

14

Positive control

480

400

620

617

294

68

51

68

282

91

* Solvent control with DMSO

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative with and without metabolic activation

Tris(2-methoxyethoxy)vinylsilane has been tested according to OECD 471 and under GLP. No increase in the number of revertants was observed in any strain with or without metabolic activation, neither in the preliminary plate incorporation range-finding study nor in the initial and repeat preincubation assays. It is concluded that the test substance is negative for mutagenicity to bacteria under the conditions of the test.