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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:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Study period:
May 06th, 1996 - August 29th, 1996
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
GLP - Guideline study, tested with the source substanceCAS 11138-60-6. According to the ECHA guidance document “Practical guide 6: How to report read-across and categories (March 2010)”, the reliability was changed from RL1 to RL2 to reflect the fact that this study was conducted on a read-across substance.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1996
Report Date:
1996

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
no
Qualifier:
according to
Guideline:
OECD Guideline 472 (Genetic Toxicology: Escherichia coli, Reverse Mutation Assay)
Deviations:
no
GLP compliance:
yes
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Physical state: Yellow , clear liquid
- Expiration date: 01.01.2006
- Storage condition of test material: room temperature, protected from light

Method

Target gene:
Genes involved in Histidine synthesis
Species / strainopen allclose all
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Species / strain / cell type:
S. typhimurium TA 1538
Species / strain / cell type:
E. coli WP2 uvr A
Metabolic activation:
with and without
Metabolic activation system:
S9-Mix (Spraque Dawley rats, male, Aroclor 1254 induced)
Test concentrations with justification for top dose:
0, 10, 33, 100, 333 and 1000 µg/plate
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: ethanol
Controls
Negative solvent / vehicle controls:
yes
Positive controls:
yes
Positive control substance:
other: see table
Details on test system and experimental conditions:
METHOD OF APPLICATION: in medium; in agar (plate incorporation)

DURATION
- Exposure duration: 48 to 72 h
- Expression time (cells in growth medium): 48 to 72 h

DETERMINATION OF CYTOTOXICITY
- Method: Inspection of the bacterial backgroung lawn wit a dissecting microscope
Evaluation criteria:
Revertant colonies were counted and the mean and standard deviation were calculated and compared to the controls.
All Salmonella tester strains must demonstrate the presence of the deep rough mutation and the deletion of the uvrA gene. Cultures of the TA98 and TA100 strains must demonstrate the presence of the pKM101 plasmid R-factor. All WP2 uvrA cultures must demonstrate the deletion of the uvrA gene. All cultures must demonstrate the characteristic mean number of spontaneous revertants in the vehicle controls. Tester strain titers must be above 30.000.000 cells/ml. The mean of each positive control must be at least three-fold increased to the controlls. A minimum of three non-toxic dose levels are recquired to evaluate assay data.
Statistics:
Mean and standard deviation were calculated

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:
no cytotoxicity, but tested up to precipitating concentrations
Vehicle controls validity:
other: An unacceptable vehicle control value with the tester strain TA1537, contamination of tester strain TA98, experiments were repeated
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 1538
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity, but tested up to precipitating concentrations
Vehicle controls validity:
valid
Positive controls validity:
valid
Species / strain:
E. coli WP2 uvr A
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity, but tested up to precipitating concentrations
Vehicle controls validity:
valid
Positive controls validity:
valid
Additional information on results:
TEST-SPECIFIC CONFOUNDING FACTORS

- Precipitation: >100 µg/plate

RANGE-FINDING/SCREENING STUDIES: Yes

COMPARISON WITH HISTORICAL CONTROL DATA: Yes

Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Any other information on results incl. tables

Experiment 1:

With or without S9-Mix

Test substance concentration

(μg/plate)

Mean number of revertant colonies per plate

(average of 3 plates)

Base-pair substitution type

Frameshift type

TA 1535

TA1537

TA98

TA100

 

TA 1538

WP2uvrA

-

Vehicle

12

4

17

111

5

21

 

10

3

4

15

115

6

16

 

33

5

5

19

113

6

11

-

100

9

4

19

98

7

12

-

333

7

5

11

116

4

10

-

1000

8

6

21

120

7

13

Positive

controls

- S9

Name

SA

9AA

2NF

SA

2NF

MMS

Concentrations

(μg/plate)

1.0

75

1.0

1.0

1.0

1000

Number of colonies/plate

241

40

105

377

179

143

+

Vehicle

14

5

18

133

7

11

 

10

9

5

27

114

12

16

+

33

9

3

21

113

8

13

+

100

8

7

26

108

9

13

+

333

9

4

27

115

6

8

+

1000

10

5

17

111

9

13

Positive

controls

+ S9

Name

2AA

2AA

2AA

2AA

2AA

2AA

Concentrations

(μg/plate)

1.0

1.0

1.0

1.0

1.0

10

Number of colonies/plate

72

127

888

904

783

57

SA: Sodium azide

9AA : 9-Aminoacridine

MMS: Methylmethanesulfonate

2-AA: 2-Aminoanthracene

2NF: 2-Nitrofluorene

 

 

Experiment 2/3:

With or without S9-Mix

Test substance concentration

(μg/plate)

Mean number of revertant colonies per plate

(average of 3 plates)

Base-pair substitution type

Frameshift type

TA 1535

TA1537

TA98

TA100

 

TA 1538

WP2uvrA

-

Vehicle

14

10

23

126

11

27

 

10

7

13

16

117

7

27

 

33

9

15

23

124

8

19

-

100

5

13

22

120

6

18

-

333

12

9

17

110

11

16

-

1000

8

14

17

125

5

21

Positive

controls

- S9

Name

SA

9AA

2NF

SA

2NF

MMS

Concentrations

(μg/plate)

1.0

75

1.0

1.0

1.0

1000

Number of colonies/plate

429

757

125

601

221

195

+

Vehicle

8

5

19

147

14

24

 

10

9

7

17

142

16

30

+

33

10

5

19

136

18

25

+

100

10

5

20

132

13

31

+

333

10

4

17

138

12

19

+

1000

10

7

19

125

12

19

Positive

controls

+ S9

Name

2AA

2AA

2AA

2AA

2AA

2AA

Concentrations

(μg/plate)

1.0

1.0

1.0

1.0

1.0

10

Number of colonies/plate

85

97

530

647

1041

88

SA: Sodium azide

9AA : 9-Aminoacridine

MMS: Methylmethanesulfonate

2-AA: 2-Aminoanthracene

2NF: 2-Nitrofluorene

 

 

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative Under the tested experimental conditions the test substance did not induce gene mutations in S. typhimurium strains and in an E. coli strain up to the maximum of solubility. Therefore it is not considered to be mutagenic in this bacterial mutagenicity tes