Registration Dossier

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)
Rationale for reliability incl. deficiencies:
guideline study with acceptable restrictions
Remarks:
Restriction: E. coli not tested

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1993
Report Date:
1993

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

Target gene:
S. typhimurium
Species / strain
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Metabolic activation:
with and without
Metabolic activation system:
Aroclor-induced rat liver S-9 mix
Test concentrations with justification for top dose:
20 ug - 5000 ug/plate
Vehicle / solvent:
water
Controls
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
yes
Positive controls:
yes
Remarks:
with metabolic activation: 2-aminoanthracene; without metabolic activation: N-methyl-N'-nitro-N-nitrosoguanidine, 4-nitro-o-phenylendiamine and 9-aminoacridine chloride monohydrate
Details on test system and experimental conditions:
Standard Plate Test and Preincubation Test

Results and discussion

Test results
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:
other: No bacteriotoxic effect was observed.
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Additional information on results:
No precipitation of the test substance was found.
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Any other information on results incl. tables

Table: PreincubationTest (average results of 3 plates, respectively)

Concentration µg/plate

TA 1535*

TA 1535*

TA 1537

TA 98

TA 100

-S9

+S9

-S9

+S9

-S9

+S9

-S9

+S9

-S9

+S9

Solvent Control

10

11

16

16

7

11

26

43

108

129

20

14

12

23

13

7

5

28

38

108

103

100

12

10

16

17

8

9

26

37

97

99

500

16

13

17

18

8

10

24

37

87

99

2500

11

10

16

14

7

9

26

35

80

96

5000

10

12

20

14

7

10

22

41

80

93

Positive Control

493

50

987

615

163

55

602

545

669

365

*Due to the low spontaneous rate in the 2nd experiment, the preincubation assay using TA 1535 was repeated.

Table: Standard Test (average result of 3 plates, respectively)

Concentration µg/plate

TA 1535

TA 1537

TA 98

TA 100

-S9

+S9

-S9

+S9

-S9

+S9

-S9

+S9

Solvent Control

18 18 11 9 30 42 105 111

20

19 20 10 9 29 47 103 118

100

17 19 11 10 27 35 103 107

500

18 17 9 9 29 35 96 84

2500

17 18 10 11 31 35 117 94

5000

17 19 9 9 30 33 108 96

Positive Control

1637 105 579 99 1347 628 1164 873

Applicant's summary and conclusion

Conclusions:
Interpretation of results: negative
According to the results of the present study, the test substance 2-Ethylimidazol is not mutagenic in the Ames test under the experimental conditions chosen here.