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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
Study period:
1994/03/23 - 1994/05/31
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
The registered substance is a UVCB material which contains substances of varying chain length. Read across was performed to an analogous material whose carbon chain length differs by an average of two CH2-groups from the registered substance. Because of the UVCB nature of these substances, the components of the registered substance were also present in the test material, albeit at slightly different concentration levels. In addition, the test material used in this particular study was the disodium salt of the substance used as read across material for the other endpoints.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1994
Report Date:
1994

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
yes
Principles of method if other than guideline:
Only four bacterial strains were tested. But these were two strains each with base pair substitution and frameshift mutation and thus did not influence the quality and validity of the study.
GLP compliance:
yes
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent

Method

Species / strain
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Additional strain / cell type characteristics:
not specified
Metabolic activation:
with and without
Metabolic activation system:
S9 mix (Aroclor 1254 induced)
Test concentrations with justification for top dose:
0, 4, 20, 100, 500, 2500, 5000 µg/plate
(all doses were tested in triplicates)
Vehicle / solvent:
bi-distilled water
Controlsopen allclose all
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
not specified
Positive controls:
yes
Positive control substance:
other: 2- aminoanthracene
Remarks:
TA 98, TA 100, TA 1535, TA 1537 with S9
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
not specified
Positive controls:
yes
Positive control substance:
9-aminoacridine
Remarks:
TA 1537 without S9

Migrated to IUCLID6: 9AA
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
not specified
Positive controls:
yes
Positive control substance:
sodium azide
Remarks:
TA 100, TA 1535 without S9

Migrated to IUCLID6: NaN3
Details on test system and experimental conditions:
Test group

Top agar was prepared for the Salmonella strains by mixing 100 mL agar (0.6 % agar, 0.5 % NaCI) with 10 mL of a 0.5 mM histidine-biotin solution.
The following ingredients were added (in order) to 2 mL of molten top agar at approx. 45 °C:

0.1mL of an overnight nutrient broth culture of the bacterial tester strain
0.1 mL test compound solution
0.5 mL S-9 Mix (if required) or buffer

After mixing, the liquid was poured into a petridish with minimal agar (1.5 % agar, Vogel-Bonner E medium with 2 % glucose). After incubation for approximatly 48 hours at approx. 37 °C in the dark, colonies (his* revertants) were counted.
Two independent experiments were performed.

Positive controls

Positive control plates were included for each strain. The following substances were used as positive controls.
a) without metabolic activation:
Sodium-azide: TA 100, TA 1535 9-Aminoacridine: TA 1537 2-Nitrofluorene: TA 98
b) with metabolic activation:
2-Aminoanthracene: TA 98, TA 100, TA 1535, TA 1537

Negative controls

a) solvent controls (0 microgram/plate)
b) untreated controls
Evaluation criteria:
A test article is classified mutagenic if either of the following conditions under a) and b) is achieved:

a) a test article produces at least a 2-fold increase in the mean number of revertants per plate of at least one of the tester strains over the mean number of revertants per plate of the appropriate vehicle control at complete bacterial background lawn

b) a test article induces a dose-related increase in the mean number of revertants per plate of at least one of the tester strains over the mean number of revertants per plate of the appropriate vehicle control in at least two to three concentrations of the test article at complete bacterial background lawn.
The test results must be reproducible.

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:
.TEST-SPECIFIC CONFOUNDING FACTORS
- Water solubility: test substance did not precipitate on the plates up to the highest investigated dosis
- Precipitation: no

RANGE-FINDING/SCREENING STUDIES: The substance proved to be toxic for the bacterial strain TA 100 in the absence of a metabolizing system at a dose of 5000µg/plate only in the cytotoxic experiment. Therefore 5000 µg/plate was chosen as the highest dose in the experiment.
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative

The test substance did not induce mutations in any of the test strains at any concentration.
Executive summary:

The test substance was investigated for its mutagenicity in accordance with OECD guideline 471 in test strains TA 98, TA 100, TA 102, TA 1537 and TA 1538 in two independant experiments. None of the test strains showed an increased mutation rate at any test concentration. The respective positive controls were valid. The test substance is considered to be non mutagenic in this test system.