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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
Reliability:
2 (reliable with restrictions)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1984
Report date:
1984

Materials and methods

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

Test material

Constituent 1
Chemical structure
Reference substance name:
1,3,4-Thiadiazole-2(3H)-thione, 5-(tert-dodecyldithio)-
EC Number:
813-543-0
Cas Number:
73984-93-7
Molecular formula:
C14H26N2S4
IUPAC Name:
1,3,4-Thiadiazole-2(3H)-thione, 5-(tert-dodecyldithio)-
Test material form:
liquid

Method

Target gene:
Not reported.
Species / strainopen allclose all
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Additional strain / cell type characteristics:
not applicable
Species / strain / cell type:
S. typhimurium TA 1538
Additional strain / cell type characteristics:
not applicable
Species / strain / cell type:
E. coli WP2 uvr A
Additional strain / cell type characteristics:
not applicable
Metabolic activation:
with and without
Metabolic activation system:
S9 Mix
Test concentrations with justification for top dose:
10, 50, 100, 500, 1000 and 5000 µg/plate
Vehicle / solvent:
DMSO was used as vehicle.
Controlsopen allclose all
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
Positive controls:
yes
Positive control substance:
sodium azide
Positive control substance:
9-aminoacridine
Positive control substance:
2-nitrofluorene
Positive control substance:
2-acetylaminofluorene
Details on test system and experimental conditions:
The test was carried out using the poured plate method. The test was performed with and without metabolic activiation using S9 Mix. Bacterial suspension (0.1 mL), test solution (0.1 mL) and sodium phosphonate buffer or S9 Mix (0.5 mL) was added to each plate with top agar (2.0 mL). The plates were then incubated for 48 h at 37 °C.
Evaluation criteria:
The number of revertant colonies were then counted.
Statistics:
No statistical methods were reported.

Results and discussion

Test resultsopen allclose all
Species / strain:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
not determined
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:
not determined
Vehicle controls validity:
valid
Untreated negative controls validity:
not applicable
Positive controls validity:
valid
Species / strain:
E. coli WP2 uvr A
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
not determined
Vehicle controls validity:
valid
Untreated negative controls validity:
not applicable
Positive controls validity:
valid
Additional information on results:
The test substance showed no evidence of mutagenic activity when tested in bacterial systems.
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Any other information on results incl. tables

Table 1: Mean Revertant Colonies

Material

Test concentration (µg/plate)

With or without S9 mix

Reverse mutation (number of colonies)

Base pair exchange type

Frame shift type

TA100

TA1535

WP2

TA98

TA1537

TA1538

Solvent control

 

-

110

16

24

24

14

16

Test compound

10

-

100

12

30

19

9

16

50

-

93

16

29

14

19

10

100

-

86

12

26

20

13

12

500

-

94

6

28

19

11

17

1000

-

89

11

30

18

9

12

5000

-

108

10

22

20

7

8

Solvent control

 

+

84

10

28

20

18

13

Test compound

10

+

89

4

30

17

22

14

50

+

92

8

20

23

14

20

100

+

92

4

26

20

10

12

500

+

100

6

28

24

14

14

1000

+

100

6

28

21

16

15

5000

+

98

6

23

18

4

10

Reported value is the mean of duplicate plates
- = absence, + = presence

Positive controls

Not requiring S9 Mix

Name

AF-2

NaN3

AF-2

AF-2

9AA

2NF

Concentration (µg/plate)

0.01

0.5

0.04

0.1

80

2

Number of colonies/plate

499

362

550

525

>1000

806

Requiring S9 Mix

Name

AF-2

NaN3

AF-2

AF-2

9AA

2NF

Concentration (µg/plate)

0.5

2

80

0.5

2

0.5

Number of colonies/plate

486

241

>1000

330

213

558

AF-2 = 2 -aminofluorene; NaN3 = sodium azide; 9AA = 9 -aminoacridine; 2NF = 2 -nitrofluorene

(Author note: the results reported for the positive controls 9AA (without S9 mix) and AF-2 (with S9 mix) at 80 µg/plate appear in the study report as '1000<', the author has assumed that this was intended to state >1000 as shown in the table above)

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative

The study report describes a valid guideline study. No information about GLP compliance is available. It was concluded that the test material showed no evidence of mutagenic activity when tested in bacterial test systems.
Executive summary:

An Ames metabolic activation test to assess the potential mutagenic effect of the test material was conducted using a similar procedure to that described in the current OECD Guideline 471. The test material (CAS No. 73984 -93 -7) was tested in 5 strains of Salmonella typhimurium and one strain of Escherichia coli. The test material was dissolved in dimethyl sulphoxide and was tested at 10, 50, 100, 500, 1000 and 5000 µg/plate using the poured plate method, with and without metabolic activation. Solvent controls and positive controls were included in the test. It was concluded that the test material showed no evidence of mutagenic activity when tested in bacterial test systems.