Registration Dossier

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
Study period:
12.08.-05.09.1986
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
comparable to guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1986
Report Date:
1986

Materials and methods

Test guidelineopen allclose all
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 472 (Genetic Toxicology: Escherichia coli, Reverse Mutation Assay)
GLP compliance:
yes
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent

Method

Species / strainopen allclose all
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Species / strain / cell type:
S. typhimurium TA 1538
Species / strain / cell type:
E. coli WP2 uvr A
Metabolic activation:
with and without
Metabolic activation system:
rat liver S9-mix
Test concentrations with justification for top dose:
1st experiment: 4 - 10000 µg/plate
2nd experiment: 4 - 5000 µg/plate
Vehicle / solvent:
Tested substance suspended in 100 µL ethanol
Controlsopen allclose all
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
9-aminoacridine
2-nitrofluorene
sodium azide
benzo(a)pyrene
other: N-methyl-N'-nitro-N-nitrosoguanidine=MNNG: WP2uvrA
Remarks:
without metabolic activation
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
benzo(a)pyrene
other: 2-aminoanthracene; all strains
Remarks:
with metabolic activation
Details on test system and experimental conditions:
Method of application: in agar (plate incorporation)
Duration of incubation: 48h - 72h at 37°C in the dark

Determination of cytotoxicity:
1. experiment: reduction of spontaneous revertants or clearing of the bactarial background lawn
2. experiment: surving fraction (comparision of number of colonies between plates of solvent control and substance)
Evaluation criteria:
Increase of revertant colonies
Statistics:
Number of colonies per plate for each strain as well as mean values of the colonies of 3 plates/dose were counted, corrected to the next higher integer.

Results and discussion

Test resultsopen allclose all
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:
not examined
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 1538
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
not examined
Positive controls validity:
valid
Species / strain:
E. coli WP2 uvr A
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
not examined
Positive controls validity:
valid
Additional information on results:
Visible precipitation of the test compound was observed at 500 µg/plate and above
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 without metabolic activation
negative with metabolic activation

The test substance was not mutagenic in the presence and absence of a metabolising system in Salmonella typhimurium and Escherichia coli.
Executive summary:

Naphtol AS-ITR FWTR was tested for mutagenicity with the strains TA 100, TA1535, TA 1537, TA 1538, TA 98 of Salmonella typhimurium and Escherichia coli WP2uvrA.

The mutagenicity studies were conducted in the absence and in the presence of a metabolizing system derived from rat liver homogenate. A dose range of 6 different doses from 4 ~g/plate to 5 000 ~g/plate was used.

Toxicity: The test compound proved to be not toxic to most of the bacterial strains. 5 000 ~g/plate was chosen as top dose level for the mutagenicity study in the second experiment.

Mutagenicity: In the absence of the metabolic activation system the test compound did not show a dose dependent increase in the number of revertants in any of the bacterial strains. Also in the presence of a metabolic activation system, treatment of the cells with Naphtol AS-ITR FWTR did not result in relevant increases in the number of revertant colonies.

It can be stated that Naphtol AS-ITR FWTR is not mutagenic in these bacterial test systems neither with nor without exogenous metabolic activation at the dose levels investigated.