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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 based on grouping of substances (category approach)
Adequacy of study:
key study
Study period:
1996
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: The study was conducted according to the appropriate OECD test guideline, and in compliance with GLP.

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)
Version / remarks:
1983
Qualifier:
according to
Guideline:
EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria)
Version / remarks:
1993
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: strains TA 98, TA 100, TA 1535, TA 1537, and TA 102
Metabolic activation:
with and without
Metabolic activation system:
Aroclor induced rat liver S9
Test concentrations with justification for top dose:
1.25 to 5000 µg/plate (200 µg/plate for TA 1537)
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: DMSO
- Justification for choice of solvent/vehicle: none given in report
Controlsopen allclose all
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
sodium azide
Remarks:
TA 100 and TA 1535 without metabolic activation

Migrated to IUCLID6: 2 µg/plate
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: 2-aminoanthracene, 5 µg/plate
Remarks:
TA 1537 without metabolic activation
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
9-aminoacridine
Remarks:
TA 98, TA 100 with metabolic activation

Migrated to IUCLID6: 50 µg/plate
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
2-nitrofluorene
Remarks:
TA 98 without metabolic activation

Migrated to IUCLID6: 50 µg/plate
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: glutaraldehyde 25 µg/plate
Remarks:
TA 102 without metabolic activation
Details on test system and experimental conditions:
ACTIVATION: The activity of the post-mitochondrial fraction was checked by the supplier. S9 mix contained 10% S9 fraction. 0.5 ml S9 mix was added to 2.5 ml of agar.

METHOD OF APPLICATION: in agar (plate incorporation); preincubation (Experiment 2 with metabolic activation)

DURATION
- Preincubation period: 1 h
- Exposure duration: 3 days
- Expression time (cells in growth medium): 3 days

SELECTION AGENT (mutation assays): histidine-deficient agar

NUMBER OF REPLICATIONS: Triplicate plates, experiment repeated

DETERMINATION OF CYTOTOXICITY
- Method: other: condition of bacterial lawn and/or reduction in the number of revertants.
Evaluation criteria:
Considered to be mutagenic if test was valid and reproducible and Dunnetts test gave a positive response (p<0.01) with a significant dose correlation.

Results and discussion

Test results
Species / strain:
S. typhimurium, other: TA 98, TA 100, TA 1535, TA 1537, and TA 102
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
from 10 µg/plate (TA 1537)
Vehicle controls validity:
valid
Untreated negative controls validity:
not applicable
Positive controls validity:
valid
Additional information on results:
PRECIPITATION CONCENTRATION: Precipitation observed at 1000 µg/plate and above.

CYTOTOXIC CONCENTRATION:
- With and without metabolic activation: There was variability in the toxic response of the various tester strains to Dobanol 25. As a result, in the second experiment various additional dose levels were added. Strain TA 1537 was particularly sensitive and slight toxicity was observed at 10 µg/plate. There was no obvious toxicity with TA 1535 up to 1000 µg/plate although slight toxic effects may have been obscured by precipitation at this level and above. Toxic effects were seen in TA98 and 100 with S9 at 250 µg/plate and with TA102 at 62.5 µg/plate +S9 and at 250 µg/plate -S9. It was concluded that a sufficient number of dose levels were assessed where toxicity did not confound the result.
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Any other information on results incl. tables

Table 1 Experiment 1 Plate incorporation: Number of revertants per plate (mean of 3 plates)

Strain

TA98

TA100

TA1535

TA1537 *

TA102

TA98

TA100

TA1535

TA1537

TA102

Dose

- MA

+MA

0

11.8

88.8

10.6

6.2

317.2

23.2

98.6

17.6

14

448

0.32

NT

NT

NT

8.7

NT

NT

NT

NT

NT

NT

1.6

NT

NT

NT

8

NT

NT

NT

NT

NT

NT

8

13.7

78.7

16

8

293.3

28

103

12.3

12.3

399.3

40

13

93

13.7

8.3

338.7

22.7

107.3

14.3

11.3

301

200

10.3

65

13.3

9

289

19.7

95

15

8.7

304.7

1000

10

56.7

13.7

NT

246.7

15

78

13.7

9.3

266.7

5000

7

48.7

11

NT

195

13.7

79

11.3

7.7

221

Positive control

1289.7

637.7

454

603.3

811.3

1154.3

1573

NT

NT

NT

NT Not tested

Table 2 Experiment 2 Plate incorporation, without activation: Number of revertants per plate (mean of 3 plates)

Strain

TA98

TA100

TA1535

TA1537 *

TA102 *

Dose

 - MA

0

15.6

85.4

6.8

10

325.6

62.5

13.3

60.7

9

(2.5) 9.7

(12.5) 292.3

125

12.3

76.7

8.7

(5) 7

(25) 280

250

11.7

55.3

7.7

(10) 9

(50)  292.7

500

9

63.3

6.7

(20) 11.3

(100} 295.3

1000

5.7

57.7

9

(40) 5.7

(200) 253.7

Positive control

1231.3

615.3

474.7

610

1002.7

Figures in brackets indicate doses where these differ from column 1

NT Not tested

Table 3 Experiment 2 Pre-incubation, with activation: Number of revertants per plate (mean of 3 plates)

 

Strain

TA98 *

TA100 *

TA1535

TA1537 *

TA102 *

Dose

+ MA

0

18

106.4

12.8

12

344

6.25

NT

NT

NT

NT

368

12.5

19.3

109

(62.5) 15

(1.25) 7

340

25

24

97

(125) 19.3

(2.5) 5

317

50

21.3

100.7

(250) 9

(5) 11.7

327

100

16.7

99

(500) 16.7

(10) 8

304

200

12.7

92.3

(1000) 11.7

(20) 6

NT

Positive control

620.3

470.7

NT

NT

NT

Figures in brackets indicate doses where these differ from column 1

NT Not tested

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative with and without metabolic activation

In a valid and reliable study according to OECD TG 171 and under GLP, C12-16 alcohol Dobanol 25 did not increase the reverse mutation rate in histidine dependent bacterial strains of Salmonella typhimurium in the presence or absence of metabolic activation at dose levels including those which showed some degree of cytotoxicity. The results of the initial plate incorporation experiment were confirmed in the independent repeat experiment which used the plate incorporation method without metabolic activation and the pre-incubation method with metabolic activation. It is concluded that the test substance is negative for mutagenicity to bacteria.