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Toxicological information

Genetic toxicity: in vitro

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Administrative data

Endpoint:
in vitro gene mutation study in bacteria
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study with acceptable restrictions
Remarks:
Non-GLP and no E.coli strain tested, otherweise fully adequate for assessment

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1991
Report Date:
1991

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
GLP compliance:
no
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Analytical purity: 100%
- Storage condition of test material: room temperature

Method

Target gene:
his+
Species / strain
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Metabolic activation:
with and without
Metabolic activation system:
Aroclor-induced rat liver S-9 mix
Test concentrations with justification for top dose:
0, 20, 100, 500, 2500 and 5000 µg/plate (standard plate test and preincubation test)
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: DMSO
Controlsopen allclose all
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
Remarks:
DMSO
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: 2-aminoanthracene
Remarks:
with S9 mix; all strains
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: N-methyl-N-nitro-N-nitrosoguanidine
Remarks:
without S9 mix; TA 1535 and TA 100
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: 4-nitri-o-phenylenediamine
Remarks:
without S9 mix; TA 98
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
9-aminoacridine
Remarks:
without S9 mix; TA 1537
Details on test system and experimental conditions:
METHOD OF APPLICATION: in agar (plate incorporation); preincubation

DURATION
Plate incorporation method:
- Exposure duration: ca. 48 hours at 37°C
Preincubation method:
- Preincubation period: 20 minutes at 37°C
- Exposure duration: ca. 48 hours at 37°C

NUMBER OF REPLICATIONS: 3

DETERMINATION OF CYTOTOXICITY
reduced his background growth
Evaluation criteria:
In general, a substance to be characterized as positive in the Ames test has to fulfill the following requirements:
- doubling of the spontaneous mutation rate (control)
- dose-response relationship
- reproducibility of the results.

Results and discussion

Test results
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
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Additional information on results:
Toxicity
No bacteriotoxic effect (reduced his background growth) was observed.

Solubility
Incomplete solubility of test substance in DMSO was observed from about 100 µg/plate onward.

Any other information on results incl. tables

Standard Plate Test:

TA 1535 TA 100 TA 1537 TA 98
Dose (µg/plate) -S9 +S9 -S9 +S9 -S9 +S9 -S9 +S9
0 18 16 95 108 9 19 24 39
20 16 19 99 118 10 15 24 35
100 20 21 111 112 10 12 24 41
500 23 19 80 82 10 13 17 37
2500 20 20 88 85 8 10 13 39
5000 25 19 77 85 7 11 22 38
2-AA 281 1250 283 1474
MNNG 2423 1508
AAC 488
NPD 1328

Preincubation Test:

TA 1535 TA 100 TA 1537 TA 98
Dose (µg/plate) -S9 +S9 -S9 +S9 -S9 +S9 -S9 +S9
0 14 14 124 123 11 12 28 42
20 16 18 111 86 11 12 25 31
100 19 18 118 94 11 14 19 29
500 19 16 85 79 10 14 17 30
2500 14 20 83 76 9 12 16 28
5000 14 14 75 81 7 10 14 31
2-AA 192 1161 123 794
MNNG 959 995
AAC 493
NPD 855

Controls:

2-AA: 2 aminoanthracene (10 µg/plate)

MNNG: N-methyl-N'-nitro-N-nitrosoguanidine (5 µg/plate)

AAC: aminoacridine (100 µg/plate)

NPD: 4-nitro-o-phenylendiamine (10 µg/plate)

Applicant's summary and conclusion

Conclusions:
Under the conditions chosen, the test substance was not mutagenic in the reverse bacteria mutation assay.