Benzenesulfinic acid, 4-methyl-, potassium salt (1:1)

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:

1993

Reliability:

1 (reliable without restriction)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1993

Report date:

1993

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of assay:

bacterial gene mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Potassium 4-methylbenzenesulfinate

EC Number:

700-509-4

Cas Number:

19294-29-2

Molecular formula:

C7H7KO2S

IUPAC Name:

Potassium 4-methylbenzenesulfinate

Details on test material:

- Name of test material (as cited in study report): CGA 311117 tech.
- Physical state: solid
- Purity: 98.5%
- Lot/batch No.: V.24-30-10

Method

Species / strain

Species / strain 1

Species / strain / cell type:

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

Details on mammalian cell type (if applicable):

- Type and identity of media:

Without metabolic activation:
Strain Mutagen Solvent
TA 100 sodium azide distilled water
TA 1535 sodium azide distilled water
TA 98 2-nitrofluorene DMSO
TA 1537 9 (5)-aminoacridine DMSO

With metabolic activation:
Strain Mutagen Solvent
TA 100 2-aminoanthracene DMSO
TA 1535 cyclophosphamide*H2O bidistilled water
TA 98 2-aminoanthracene DMSO
TA 1537 2-aminoanthracene DMSO

Species / strain 2

Species / strain / cell type:

E. coli WP2 uvr A

Details on mammalian cell type (if applicable):

- Type and identity of media:

Without metabolic activation:
Strain Mutagen Solvent
WP2 uvrA 4-nitroquinoline-N-oxide DMSO

With metabolic activation:
Strain Mutagen Solvent
WP2 uvrA 2-aminoanthracene DMSO

Metabolic activation:

with and without

Test concentrations with justification for top dose:

Range in cytotoxicity test: 20.6 - 5000µg/plate

Range in mutagenicity test:
Without metabolic activation: 312.5-5000µg/plate
With metabolic activation:: 312.5-5000µg/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: bidistilled water

Controls

Controls 1

Untreated negative controls:

yes

Remarks:

solvent alone

Positive controls:

yes

Positive control substance:

sodium azide

Remarks:

Migrated to IUCLID6: without metabolic activation for TA 100 and TA 1535

Controls 2

Untreated negative controls:

yes

Remarks:

sovent alone

Positive controls:

yes

Positive control substance:

4-nitroquinoline-N-oxide

Remarks:

Migrated to IUCLID6: without metabolic activation for WP2 uvrA

Controls 3

Untreated negative controls:

yes

Remarks:

solvent alone

Positive controls:

yes

Positive control substance:

2-nitrofluorene

Remarks:

Migrated to IUCLID6: without metabolic activation for TA 98

Controls 4

Untreated negative controls:

yes

Remarks:

solvent alone

Positive controls:

yes

Positive control substance:

9-aminoacridine

Remarks:

Migrated to IUCLID6: without metabolic activation for TA 1537

Controls 5

Untreated negative controls:

yes

Remarks:

solvent alone

Positive controls:

yes

Positive control substance:

other: 2-aminoanthracene: with metabolic activation for TA 100, WP2 uvrA, TA 98 and TA 1537

Controls 6

Untreated negative controls:

yes

Remarks:

solvent alone

Positive controls:

yes

Positive control substance:

cyclophosphamide

Remarks:

Migrated to IUCLID6: with metabolic activation for TA 1535

Details on test system and experimental conditions:

Control of genotype:
- Characteristics of the strains were checked monthly

Method of application: in agar (plate incorporation)

Metabolic activation mixture:
Rat liver S9 fraction (100µl/ml), NADP (4µmol/ml), MgCl2 (8µmol/ml), KCl (33µmol/ml), Na-phosphate buffer pH 7.4 (100µmol/ml), glucose-6-phosphate (5µmol/ml)

Duration:
- Incubation period: 48 hr at 37 ± 1.5°C inverted in darkness

Assay acceptance criteria:
A test is considered acceptable if the mean colony counts of the negative control values of all strains are within the acceptable ranges and if the results of the positive controls meet the criteria for a positive response.

Evaluation criteria:

Criteria for a positive response - the substance was deemed to be mutagenic in this test if one or both of the following conditions were met:
- at least a reproducible doubling of the mean number of revertants per plate above that of the negative control at any concentration for one or more of the strains
- a reproducible increase of the mean number of revertants per plate for any concentration above that of the negative control by at least a factor of 1.5 for strain S.typhimurium TA 100

Statistics:

A statistical analysis was not performed as the use of statistical methods is not generally recommended

Results and discussion

Test results

Test results 1

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

Test results 2

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:

valid

Positive controls validity:

valid

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Applicant's summary and conclusion

Conclusions:

Based upon the results of these experiments it can be concluded that this substance and it's metabolites did not induce gene mutations in the strains of S.Typhimurium and E.coli used.

Executive summary:

The experiments were performed with and without metabolic activation. Normal background growth was observed in both strains.

None of the tested concentrations of CGA 311117 tech. led to an increase in the incidence of either histidine- or tryptophan- prototrophic mutants by comparison with the negative control.

There were no known circumstances or occurrances in this study that were considered to have affected the quality or integrity of the data.

Based upon the results of these experiments there is no evidence to suggset this substance should be classed as either cytotoxic nor mutagenic.