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Toxicological information

Genetic toxicity: in vitro

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Administrative data

Endpoint:
in vitro gene mutation study in bacteria
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1986
Report Date:
1986

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
no
GLP compliance:
yes
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent

Method

Target gene:
Histidine operon
Species / strain
Species / strain / cell type:
S. typhimurium, other: TA 98, TA 100, TA 1535, TA 1537, TA 1538
Metabolic activation:
with and without
Metabolic activation system:
S9 fraction from liver homogenates of rats induced with 500 mg/kg bw Aroclor 1254
Test concentrations with justification for top dose:
0, 5, 150, 500, 150, 5000 µg/plate
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: ethanol
- Justification for choice of solvent/vehicle: solubility
Controls
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: Without S9: 2-nitrofluorene (TA98 & TA1538), ENNG (TA100 & TA1535), 9-aminoacridine (TA1537). With S9: 2-aminoanthracene (all strains)
Details on test system and experimental conditions:
METHOD OF APPLICATION: in agar (plate incorporation)

NUMBER OF REPLICATIONS: 2 (3 plates per concentration)

DETERMINATION OF CYTOTOXICITY
A preliminary toxicity test was performed to define the concentrations to be used for the mutagenicity study.
Evaluation criteria:
- negative and positive controls within the range of historical controls.
- positive: reproducible and significant dose related increase in revertants and/or reproducible doubling in the number of revertants compared with negative controls for one dose.

Results and discussion

Test results
Key result
Species / strain:
S. typhimurium, other: TA 98, TA 100, TA 1535, TA 1537, TA 1538
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
Positive controls validity:
valid
Additional information on results:
TPS-32 was not toxic towards the tester strains. Therefore 5000 µg/plate was chosen as the top dose level in the mutation tests. No substantial increases in revertant colony numbers of any of the five tester strains were observed following treatment with TPS-32 at any dose level, either in the presence or absence of metabolic activation (S-9 mix).

Any other information on results incl. tables

TABLE 1:Dose range finding test on TPS-32 - revertant colony counts obtained- with bacterial strains TA 1535, TA 1537, TA 1538,TA 98 and TA 100

Dose level

(µg/plate)

Metabolic•

activation

Bacterial strain

TA 1535

TA 1537

TA 1538

TA 98

TA 100

 

5000

-

16

16

4

20

107

 

500

-

11

12

7

13

115

 

50

-

20

17

9

12

92

 

5

-

12

19

8

19

111

 

Solvent

-

17

15

7

16

126

 

5000

+

13

15

14

21

120

 

500

+

21

15

10

27

122

 

50

+

19

14

10

27

141

 

5

+

19

18

13

22

127

 

Solvent

+

11

11

11

21

133

 

TABLE 2 Test 1:TPS-32 - revertant colony counts obtained per plate using bacterial strains TA 1535, TA 1537, TA 1538, TA 98 and TA 100

Strain

Dose level

(µg/plate)

Metabolic•

activation

Mean revertant

colony counts

SD

Individual revertant

colony counts

TA 1535

5000

-

9

2.5

12,9,7

1500

-

10

1.5

8,11,10

500

-

10

1.5

9,10,12

150

-

12

1.5

11,12,14

50

-

12

1.2

11,11,13

0

-

15

3.6

19,14,12

Solvent

-

15

4.0

11,15,19

5000

+

13

2.1

11,12,15

1500

+

16

2.5

16,18,13

500

+

15

3.1

12,14,18

150

+

17

0.6

17,16,17

50

+

16

1.7

17,14,17

0

+

11

2.5

11,14,9

Solvent

+

16

1.5

18,15,16

TA 1537

5000

-

15

1.7

14,14,17

1500

-

16

2.6

14,19,15

500

-

15

1.2

14,16,16

150

-

16

3.5

12,19,16

50

-

15

2.1

17,13,16

0

-

17

1.0

16,17,18

Solvent

-

16

6.4

9,19,21

5000

+

16

2.6

19,14,15

1500

+

19

4.6

14,23,20

500

+

17

4.6

18,12,21

150

+

19

4.6

24,18,15

50

+

15

4.7

19,10,17

0

+

15

1.2

14,16,14

Solvent

+

18

5.0

13,23,18

TA 1538

5000

-

3

1.0

4,2,3

1500

-

4

1.7

3,3,6

500

-

10

1.0

10,9,11

150

-

5

4.2

4,10,2

50

-

6

0.6

6,6,7

0

-

10

2.5

12,7,10

Solvent

-

7

1.0

6,8,7

5000

+

11

2.0

11,13,9

1500

+

11

4.7

9,16,7

500

+

12

1.5

12,13,10

150

+

10

2.1

11,12,8

50

+

13

4.6

18,9,12

0

+

9

4.0

10,13,5

Solvent

+

8

2.6

6,11,7

TABLE 2(continued)

Strain

Dose level

(µg/plate)

Metabolic•

activation

Mean revertant

colony counts

SD

Individual revertant

colony counts

TA 98

5000

-

15

1.2

14,16,14

1500

-

18

2.6

15,20,19

500

-

17

3.5

14,17,21

150

-

21

5.5

17,18,27

50

-

19

4.9

16,25,17

0

-

21

1.5

19,21,22

Solvent

-

21

6.0

27,15,20

5000

+

24

4.9

27,18,26

1500

+

25

3.2

24,29,23

500

+

27

1.5

27,26,29

150

+

25

0.6

25,25,26

_

50

+

23

2.0

25,23,21

0

+

21

1.5

21,23,20

Solvent

+

17

4.5

17,22,13

TA 100

5000

-

98

4.4

103,96,95

1500

-

91

9.9

102,86,84

500

-

95

7.4

92,103,89

150

-

96

3.8

100,93,94

50

-

99

7.0

107,94,96

0

-

97

5.6

103,92,96

Solvent

-

88

5.1

84,94,87

5000

+

102

2.6

103,104,99

1500

+

111

5.1

117,107,110

500

+

116

4.0

112,115,120

150

+

109

15.0

124,94,109

50

+

116

3.2

114,120,115

0

+

114

9.1

115,104,122

Solvent

+

108

9.3

116,111,98

TABLE 3 Test 1 : Mutability and sterility tests with bacterial strains TA 1535,TA 1537, TA 1538, TA 98 and TA 100

Strain

Compound

Dose level

(µg/plate)

Metabolic•

activation

Mean

revertant

colony

counts

SD

Individual

revertant

colony

counts

TA 1535

ENNG

5

-

226

24.0

216,208,253

TA 1537

9 AC

80

-

2031

10.1

2020,2040,2033

TA 1538

NF

2

-

55

2.3

52,56,56

TA 98

NF

1

-

84

7.4

92,78,81

TA 100

ENNG

3

-

314

11.0

327,309,307

TA 1535

AA

2

+

168

24.2

187,177,141

TA 1537

AA

2

+

98

8.5

101,88,104

TA 1538

AA

0.5

+

113

14.5

120,96,122

TA 98

AA

0.5

+

275

14.6

262,273,291

TA 100

AA

0.5

+

259

24.1

286,239,253

-

S-9 mix

500µl

0

0

-

TPS-32

5000

0

0

Applicant's summary and conclusion

Conclusions:
Not mutagenic
Executive summary:

In a study similar to OECD TG 471, a Salmonella typhimurium reverse mutation assay was performed with di-t-dodecyl polysulfides. S. typhimurium strains, TA98, TA100, TA1535, TA1537, and TA1538 were exposed to five concentrations of di-t-dodecyl polysulfides in the presence and absence of a metabolic activation system using plate incorporation at doses of 5 to 5,000 mg/plate. Exposure to five graded doses of di-t-dodecyl polysulfides in the presence and absence of metabolic activation, did not increase the reversion rates in any of the tester strains.