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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)
Rationale for reliability incl. deficiencies:
other: guideline study with restrictions

Data source

Referenceopen allclose all

Reference Type:
publication
Title:
Mutation tests with Salmonella using the plate-incorporation assay
Author:
Rexroat MA and Probst GS
Year:
1985
Bibliographic source:
Progress in Mutation Research 5, 201-212
Reference Type:
publication
Title:
o-TOLUIDINE CAS No: 95-53-4 SIDS Initial Assessment Report.
Author:
OECD SIDS
Year:
2006
Bibliographic source:
UNEP Publications

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
yes
Remarks:
Toxicity was not reached, no data on purity of the test substance
GLP compliance:
not specified
Type of assay:
bacterial reverse mutation assay

Test material

Constituent 1
Chemical structure
Reference substance name:
o-toluidine
EC Number:
202-429-0
EC Name:
o-toluidine
Cas Number:
95-53-4
Molecular formula:
C7H9N
IUPAC Name:
o-toluidine
Test material form:
not specified
Details on test material:
- Name of test material (as cited in study report): o-toluidine
- Analytical purity: no data

Method

Target gene:
his+
Species / strain
Species / strain / cell type:
other: TA 98, TA 100, TA 1535, TA 1537, TA 1538
Additional strain / cell type characteristics:
not specified
Metabolic activation:
with and without
Metabolic activation system:
S9 mix liver homogenates from Aroclor 1254 induced rats
Test concentrations with justification for top dose:
0, 50, 100, 500, 1000, 5000 µg/plate in DMSO
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: DMSO
Controls
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
not specified
Positive controls:
yes
Positive control substance:
other: 9-aminoacridine; 2-Nitrofluorene; N-Methyl-N'-nitro-N-nitrososguanidine. 2-Aminoanthracene
Details on test system and experimental conditions:
plate-incorporation assay
Evaluation criteria:
Criteria for a positive rsponse: A chemical was judged to have induced a positive response when a dose -related increase in revertants was observed in which the number of revertants exceeded the control values by at least tow-fold in at least two successive concentrations of the test chemical

Results and discussion

Test results
Species / strain:
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
Remarks:
> 5000 µg/plate
Vehicle controls validity:
valid
Untreated negative controls validity:
not specified
Positive controls validity:
valid
Additional information on results:
The positive controls increased mutant counts to well over those of the negative controls, and thus demonstrated the system's sensitivity and the
activity of the S9 mix.
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Any other information on results incl. tables

Tab 1. Evaluation of o-toluidine for induction of bacterial mutation using the Ames test

 

Treatment

µg/plate

Revertant colony counts (mean ± SD)a

 

TA1535

TA1537

TA1538

TA98

TA100

Test without metabolic activation

DMSOb

0.05 ml

18 ± 5

6 ± 1

15 ± 3

27 ± 6

141 ± 12

DMSOc

0.05 ml

18 ± 2

8 ± 4

13 ± 1

23 ± 2

138 ± 13

o-toluidine

50

18 ± 6

6 ± 1

13 ± 3

25 ± 5

146 ± 7

 

100

25 ± 3

10 ± 3

11 ± 4

32 ± 7

141 ± 16

 

500

28 ± 3

8 ± 4

14 ± 3

20 ± 1

140 ± 18

 

1000

27 ± 5

8 ± 2

12 ± 6

24 ± 3

130 ± 6

 

5000

35 ± 11

6 ± 1

16 ± 2

22 ± 7

153 ± 12

MNNGd

2.5

1728 ± 131

 

 

 

 

MNNG

5

3319 ± 56

 

 

 

 

9AmAcd

50

 

141 ± 28

 

 

 

9AmAc

100

 

1433 ± 47

 

 

 

2-NFd

0.5

 

 

105 ± 4

64 ± 10

 

2-NF

5

 

 

900 ± 36

603 ± 66

 

Test with metabolic activation

DMSOb

0.05 ml

20 ± 1

8 ± 2

23 ± 3

31 ± 11

102 ± 7

DMSOc

0.05 ml

17 ± 1

7 ± 1

20 ± 3

32 ± 1

118 ± 3

o-toluidine

50

15 ± 1

9 ± 4

19 ± 7

29 ± 3

118 ± 13

 

100

13 ± 4

8 ± 3

19 ± 4

32 ± 6

107 ± 4

 

500

13 ± 4

4 ± 1

19 ± 2

36 ± 1

117 ± 5

 

1000

16 ± 2

8 ± 2

21 ± 3

33 ± 1

127 ± 3

 

5000

14 ± 3

12 ± 2

22 ± 3

40 ± 9

142 ± 8

2-AAd

2.5

176 ± 15

259 ± 22

1700 ± 99

1922 ± 20

2370 ± 37

2-AA

5

202 ± 30

156 ± 38

1791 ± 88

2905 ± 53

2849 ± 100

 a Mean ± SD deviation of counts from triplicate plates. Values represent corrected counts fro 100% of the plate area.

 b DMSO control value for the tester strain plated at the initiation of plating ; c DMSO control value fo tester strain plated at the termination of plating; d In the nonactivated test MNNG served as the positive control for strains TA 1535 and TA 100; 9 AmAc was the positve control for the strain TA1537; and 2 NF served as the positive control for the strains TA1538 and TA 98. In the activated test, 2AA served as the positive control for all test strains.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative
Executive summary:

o-toluidine was tested for the induction of bacterial mutation using five histidine auxotrophs of Salmonella typhimurium TA135, TA1537, TA1538, TA100, TA98 according to OECD guideline 471 (plate incorporation methodology) with acceptable deviations (Toxicity was not reached, no data on purity of the test substance). The test was conducted with and without metabolic activation using an S9 fraction prepared from the livers of Aroclor-1254-induced rats. N-Methyl-N´-nitro-N-nitrosoguanidine (MNNG), 2-nitrofluorene (2NF), and 9-aminoacridine (9AmAc) served as the positive controls for the nonactivated test, while 2-aminoanthracene (2AA) served as the positive control for the activated test. Either with or without metabolic activation no revertants were induced by treatment with o-toluidine.