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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
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Acceptable, well documented study report which meets basic scientific principles

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1987
Report Date:
1987

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Version / remarks:
adopted in 1983
Deviations:
yes
Remarks:
(no E.coli or TA 102 strain tested, only 2-amino anthracene as positive control with metabolic activation, only one experiment)
GLP compliance:
no
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): FAT 66031/B
- Analytical purity: 88.1%
- Lot/batch No.: Mg. 636 vom 21.7.87, BSG ex Pa 34/34.
- Storage condition of test material: 4°C, light protected

Method

Target gene:
his-operon
Species / strain
Species / strain / cell type:
other: S. typhimurium TA 1535, TA 1537, TA 1538, TA 98 and TA 100
Metabolic activation:
with and without
Metabolic activation system:
cofactor supplemented post-mitochondrial fraction (S9 mix) prepared from the livers of rats treated with Aroclor 1254
Test concentrations with justification for top dose:
Pre-Experiment: 1, 3, 10, 33, 100, 333, 1000 and 5000 µg/plate
Experiment: 10.0, 100.0, 333.3, 1000.0 and 5000.0 µg/plate
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: H20 bidest
- Justification for choice of solvent/vehicle: The solvent was chosen because of its solubility properties and its relative non-toxicity to the bacteria.
Controls
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
Remarks:
bidest. water
True negative controls:
no
Positive controls:
yes
Positive control substance:
sodium azide
other: 4-nitro-o-phenylene-diamine (NOPD); 2-aminoanthracene (2AA)
Remarks:
(-S9) sodium azide (TA 1535, 100), 4-NOPD (TA 1537, 1538, 98); (+S9) 2-aminoanthracene (all strains)
Details on test system and experimental conditions:
METHOD OF APPLICATION: in agar (plate incorporation)

DURATION
- Exposure duration: 72 hours at 37°C

NUMBER OF REPLICATIONS: 3 plates per condition; only one experiment
Evaluation criteria:
A test substance is considered as mutagen if in strain TA 100 the number of reversions is at least twice as high with two concentrations of the substance, and in strains TA 1535, TA 1537, TA 1538, and TA 98 it is at least three times higher with two concentrations of the test substance as compared to the spontaneous reversion rate. If in a repeated experiment there is a clear increase in the reversion rate by factors as indicated even in only one strain, then this also leads to the substance being classified as a mutagen.
Also, a continuous dose-dependent increase in the number of revertants is regarded as an indication of possibly existing mutagenic properties of the test substance, regardless whether the highest dose induces the above described enhancement factors or not. Such findings would perhaps not be sufficient to declare the substance mutagenic. However, it recommends further testing to exclude mutagenicity.
Statistics:
Revertant colony numbers were calculated as average and standard deviation. No statistical analysis test was performed.

Results and discussion

Test results
Species / strain:
other: S. typhimurium TA 1535, TA 1537, TA 1538, 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:
valid
Untreated negative controls validity:
not examined
Positive controls validity:
valid
Additional information on results:
The test article precipitated weakly at 5000.0 µg/plate. 
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Any other information on results incl. tables

No toxic effects were observed in all strains. No reduction of revertant numbers for more than 70% was found in any strain used.The plates incubated with the test substance showed normal background growth up to 5000.0 µg/plate in the strains used with and without S9 mix. The test article did not induce an increase in revertant colony numbers in the absence and in the presence of S9 mix in all the strains used.

Results:

Dose µg/plate metabolic activation TA 1535 TA 1537 TA 1538 TA 98 TA 100
0 - 16 16 14 27 154
10 - 12 6 11 26 192
100 - 13 19 10 22 205
333.3 - 20 13 16 21 182
1000 - 18 21 10 25 187
5000 - 14 18 13 25 169
Sodium azide - 1542 1599
4-NOPD - 323 1963 1761
0 + 16 19 23 51 139
10 + 12 21 23 36 150
100 + 11 19 22 46 150
333.3 + 14 22 23 51 173
1000 + 10 22 26 41 179
5000 + 11 12 25 43 154
2-Aminoanthracene + 1025 373 2144 1928 1550

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative

The test item did not induce point mutations by base pair changes or frameshifts in the genome of the strains used. Therefore, the test substance is considered to be non-mutagenic in this Salmonella typhimurium reverse mutation assay.