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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:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2000
Report Date:
2000

Materials and methods

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

Test material

Reference
Name:
Unnamed
Type:
Constituent

Method

Target gene:
Histidine
Species / strain
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and TA 102
Metabolic activation:
with and without
Metabolic activation system:
S9-mix prepared from liver homogenates taken from Sprague-Dawley male rats aged 8 to 10 weeks, induced with Arochlor 1254
Test concentrations with justification for top dose:
5, 15, 50, 150, 500, 1500, 5000 µg/plate
Vehicle / solvent:
Ethanol was used as solvent
Controls
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
Remarks:
ethanol
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: Sodium acetate, 2-nitrofluorene, 9-aminoacridine
Details on test system and experimental conditions:
METHOD OF APPLICATION: in agar (plate incorporation)

DURATION
- Preincubation period: not applicable
- Exposure duration: 48 to 72 hours

NUMBER OF REPLICATIONS:
- Three per concentration and control

DETERMINATION OF CYTOTOXICITY
- Method: diminution of the background lawn was taken as an indication of bacteriotoxicity

Two independent experiments were performed.
Evaluation criteria:
Details on evaluation criteria are not given but should be in accordance with the publication by Ames et al. (1975), Mutation Research 32, 347-364.
Statistics:
The statistical difference between the mean number of revertants in the negative controls and the plates at each dosage level was tested using the Chi2 test (Mohn and Ellenberger 1977).

Results and discussion

Test resultsopen allclose all
Key result
Species / strain:
S. typhimurium TA 1535
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
-S9: at 500 µg/plate; +S9: at 5000g/plate
Vehicle controls validity:
valid
Untreated negative controls validity:
not applicable
Positive controls validity:
valid
Key result
Species / strain:
S. typhimurium TA 1537
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
-S9: at 1500 µg/plate; +S9: at 5000 µg/plate
Vehicle controls validity:
valid
Untreated negative controls validity:
not applicable
Positive controls validity:
valid
Key result
Species / strain:
S. typhimurium TA 98
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
-S9: at 500 mg/plate; +S9: at 5000µg/plate
Vehicle controls validity:
valid
Untreated negative controls validity:
not applicable
Positive controls validity:
valid
Key result
Species / strain:
S. typhimurium TA 100
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
-S9: at 500 µg/plate; +S9: at 5000µg/plate
Vehicle controls validity:
valid
Untreated negative controls validity:
not applicable
Positive controls validity:
valid
Key result
Species / strain:
S. typhimurium TA 102
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
-S9: at 500 g/plate; +S9: at 1500 µg/plate
Vehicle controls validity:
valid
Untreated negative controls validity:
not applicable
Positive controls validity:
valid

Any other information on results incl. tables

see attached document

Applicant's summary and conclusion

Conclusions:
The substance Neononyl acetate was not mutagenic to Salmonella typhimurium strains TA98, TA100, TA102, TA1535 and TA1537 in an Ames test in the presence and absence of metabolic activation (S9-mix).
Executive summary:

The potential of the test substance Neononyl acetate to induce reverse mutations in Salmonella typhimurium strains TA98, TA100, TA102, TA1535 and TA1537 was tested in an Ames test under GLP in accordance with OECD TG 471. The test substance was dissolved in ethanol and tested in concentrations ranging from 5 to 5000 µg/plate in the presence and absence of a metabolic activation (S9-mix obtained from liver homogenates from Sprague-Dawley male rats aged 8 to 10 weeks). All strains were incubated at 37 °C for 48 to 72 hours in three replicates. In the presence of S9-mix the substance was cytotoxic to strains TA98, 100, 102 and 1535 at 500 µg/plate and to strain TA1537 at 1500 µg/plate. In the absence of S9-mix bacteriotoxicity to strain TA102 was seen at 1500 µg/plate and toxicity to strains TA98, 100, 1535 and 1537 occurred at 5000 µg/plate. Precipitation of the test compound on the plates was not observed. The test substance did not induce a significant or dose-related increase in the mutation frequency of all tested strains in the absence or presence of S9-mix. The number of spontaneous revertants observed in the controls was comparable to historical controls. The results of the positive control substances confirmed the known reversion properties and the specificity of the tested strains as well as the activity of the metabolising system.

It was concluded that the substance Neononyl acetate under the experimental conditions of an Ames test was not mutagenic to bacteria (Salmonella typhimurium) strains TA98, TA100, TA102, TA1535 and TA1537 in the absence and presence of metabolising system S9-mix.