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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:
1985
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: comparable to guideline study with acceptable restrictions (limited details of study protocol, only plate incorporation protocol [preincubation is recommended for azo-dyes], no GLP; purity not specified)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1985
Report Date:
1985

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
yes
Remarks:
only plate incorporation protocol, limited documentation
GLP compliance:
no
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Analytical purity: commercial grade
- Lot/batch No.: Kores sample TS 884
- Stability under test conditions: ensured

Method

Species / strain
Species / strain / cell type:
other: S. typhimurium TA 1535, TA 1537, TA 98, TA 102 and TA 100
Metabolic activation:
with and without
Metabolic activation system:
1 ml activation mixture contains: 0.3 ml S9 fraction of liver from rats induced with Aroclor 1254 and 0.7 ml of a solution of co-factors
Test concentrations with justification for top dose:
First experiment; preliminary toxicity test: 0.08 - 5000 µg/plate
Second experiment; main experiment: 20, 78, 313, 1250 and 5000 µg/plate
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: DMSO (suspension)
Controls
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: Without S9-mix: 5 and 10 µg DR for TA 98; 0.125 and 0.25 µg 4-NQO for TA 100; 0.5 and 1.0 µg MMC for TA 102; 2.5 and 5.0 µg SA for TA 1535; for 50 and 100 µg 9AA for TA 1537.
Remarks:
Positive control substances without S9-mix (continue): : 5 µg 2-AA for TA 98, TA 100 and TA 1537; 20 µg 2-AA for TA 102 and 250 µg CCP for TA 1535.
Details on test system and experimental conditions:
METHOD OF APPLICATION: in agar (plate incorporation), in triplicates

DURATION
- Exposure duration: 48 hours at 37 °C

SELECTION AGENT (mutation assays): histidine deprivation

DETERMINATION OF CYTOTOXICITY
- Method: cloning efficiency
Evaluation criteria:
Doubling of the colony number is given as a cut-off value in the report.
Statistics:
When the colonies had been counted, the arithmetic mean was calculated.

Results and discussion

Test results
Species / strain:
other: S. typhimurium TA 1535, TA 1537, TA 98, TA 102 and TA 100
Metabolic activation:
with and without
Genotoxicity:
negative
Remarks:
no increase in the number of revertants in test groups in comparison with the negative control treatment was observed
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
a growth-inhibiting effect of the test substance was observed with strain TA 102 in the experiments without and with microsomal activation at the highest concentration.
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Additional information on results:
TEST-SPECIFIC CONFOUNDING FACTORS
- Precipitation: at the concentrations of 78µg/plate and above, the substance precipitated in soft agar.
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Any other information on results incl. tables

Table 1: Salmonella/mammalian-microsome mutagenicity test

Metabolic activation

Test substance concentration (µg/plate)

Number of revertants per plate (arithmetic mean)

TA 98

TA 100

TA 102

TA 1535

TA 1537

 

 

Without S9-mix

Negative control (DMSO)

23

143

261

14

10

20 µg/plate

30

138

270

16

10

78 µg/plate

25

136

260

19

8

313 µg/plate

22

128

244

14

6

1250 µg/plate

25

132

288

13

8

5000 µg/plate

30

125

192

12

5

Corresponding positive control

450-758

563-1149

694-1090

746-869

31-646

 

 

With

S9-mix

Negative control (DMSO)

50

142

232

9

15

20 µg/plate

49

138

339

13

20

78 µg/plate

48

140

364

9

15

313 µg/plate

47

123

312

11

7

1250 µg/plate

56

133

306

15

12

5000 µg/plate

53

109

87

17

9

Corresponding positive control

963

1266

1485

482

63

 

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative