4-amino-2,5-dichloro-N,N-dimethylbenzenesulphonamide

Genetic toxicity: in vitro

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:

from July 29, 2011 to August 12, 2011

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: well performed GLP and OECD guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2011

Report date:

2011

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria)

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.5100 - Bacterial Reverse Mutation Test (August 1998)

Deviations:

no

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

4-amino-2,5-dichloro-N,N-dimethylbenzenesulphonamide

EC Number:

247-501-2

EC Name:

4-amino-2,5-dichloro-N,N-dimethylbenzenesulphonamide

Cas Number:

26175-68-8

Molecular formula:

C8H10Cl2N2O2S

IUPAC Name:

4-amino-2,5-dichloro-N,N-dimethylbenzene-1-sulfonamide

Details on test material:

- Name of test material (as cited in study report): 4-Amino-2,5-dichloro-N,N-dimethylbenzenesulphonamide, trocken

Method

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:

phenobarbital induced rat S9 liver microsomal fraction

Test concentrations with justification for top dose:

Experiment I:
31.6, 100, 316, 1000, 2500 and 5000 µg/plate

Experiment II:
10.0, 31.6, 100, 316, 1000, 2500 and 5000 µg/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: DMSO

Controls

Untreated negative controls:

yes

Remarks:

A. dest.

Negative solvent / vehicle controls:

yes

Remarks:

DMSO

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: Positive control without metabolic activation: sodium azide for tester strains TA100, TA1535; 4-nitro-o-phenylene-diamine for TA98, TA1537; methylmethanesulfonate for TA102. Positive control with metabolic activation: 2-aminoanthracene for all strains

Details on test system and experimental conditions:

experiment I: plate incorporation test
experiment II: pre-incubation test

In two independent experiments several concentrations of the test item were used. Each assay was conducted with and without metabolic activation. The concentrations, including the controls, were tested in triplicate.

Evaluation criteria:

The Mutation Factor is calculated by dividing the mean value of the revertant counts through the mean values of the solvent control (the exact and not the rounded values are used for calculation).

A test item is considered as mutagenic if:

- a clear and dose-related increase in the number of revertants occurs and/or
- a biologically relevant positive response for at least one of the dose groups occurs in at least one tester strain with or without metabolic activation.


A biologically relevant increase is described as follows:

- if in tester strains TA 98, TA 100 and TA 102 the number of reversions is at least twice as high
- if in tester strains TA 1535 and TA 1537 the number of reversions is at least three times higher

than the reversion rate of the solvent control.

According to OECD guidelines, the biological relevance of the results is the criterion for the interpretation of results, a statistical evaluation of the results is not regarded as necessary.

A test item producing neither a dose related increase in the number of revertants nor a reproducible biologically relevant positive response at any of the dose groups is considered to be non-mutagenic in this system.

Statistics:

According to OECD guidelines a statistical evaluation of the results is not regarded as necessary.

Results and discussion

Test results

Species / strain:

S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and TA 102

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

Precipitation of the test item was observed in all tester strains used in experiment I and II (with and without metabolic activation) on the agar plates with the unaided eye. In experiment I and II precipitation of the test item was found at concentrations of 2500 µg/plate and higher (without metabolic activation) and at a concentration of 5000 µg/plate (with metabolic activation).

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

In conclusion, it can be stated that during the described mutagenicity test and under the experimental conditions reported, 4-Amino-2,5-dichloro-N,N-dimethylbenzenesulphonamide, trocken did not cause gene mutations by base pair changes or frameshifts in the genome of the tester strains used.

Therefore, 4-Amino-2,5-dichloro-N,N-dimethylbenzenesulphonamide, trocken is considered to be non-mutagenic in this bacterial reverse mutation assay.

Executive summary:

In order to investigate the potential of 4-Amino-2,5-dichloro-N,N-dimethylbenzenesulphonamide, trocken for its ability to induce gene mutations the plate incorporation test (experiment I) and the pre-incubation test (experiment II) were performed with the Salmonella typhimurium strains TA 98, TA 100, TA 1535, TA 1537 and TA 102.

In two independent experiments several concentrations of the test item were used. Each assay was conducted with and without metabolic activation. The concentrations, including the controls, were tested in triplicate. The following concentrations of the test item were prepared and used in the experiments:

Experiment I:

31.6, 100, 316, 1000, 2500 and 5000 µg/plate

Experiment II:

10.0, 31.6, 100, 316, 1000, 2500 and 5000 µg/plate

Precipitation was observed in all tester strains used in experiment I and II (with and without metabolic activation).

Toxic effects of the test item were noted in some tester strains used in experiment I and II:

• In experiment I toxic effects of the test item were observed at concentrations of 2500 µg/plate and higher (without metabolic activation), depending on the particular tester strain

•  In experiment II toxic effects of the test item were noted at concentrations of 316 µg /plate and higher (without metabolic activation) and at concentrations of 2500 µg/plate (with metabolic activation), depending on the particular tester strain.

No biologically relevant increases in revertant colony numbers of any of the five tester strains were observed following treatment with 4-Amino-2,5-dichloro-N,N-dimethylbenzenesulphonamide, trocken at any concentration level, neither in the presence nor absence of metabolic activation in experiment I and II.

The reference mutagens induced a distinct increase of revertant colonies indicating the validity of the experiments.

In conclusion, it can be stated that during the described mutagenicity test and under the experimental conditions reported, 4-Amino-2,5-dichloro-N,N-dimethylbenzenesulphonamide, trocken did not cause gene mutations by base pair changes or frameshifts in the genome of the tester strains used.

Therefore, 4-Amino-2,5-dichloro-N,N-dimethylbenzenesulphonamide, trocken is considered to be non-mutagenic in this bacterial reverse mutation assay.