Disodium peroxodisulphate

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

02-05-1990 to 13-08-1990

Reliability:

1 (reliable without restriction)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1990

Report date:

1990

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: FIFRA Guideline 84-1

Deviations:

no

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Method

Target gene:

A Salmonella Mammalian-Mircosome Mutagenicity Assay (Ames test) was conducted with sodium persulfate, E608244, Lot 0021. Five tester strains of Salmonella typhimurium: TA98, TA100, TA1535, TA1537 and TA1538 were utilized. The assay was conducted in the presence and absence of metabolic activation by Aroclor 1254 induced rat liver microsomes.

Species / strain

Species / strain 1

Species / strain / cell type:

S. typhimurium TA 1538

Details on mammalian cell type (if applicable):

Not applicable

Additional strain / cell type characteristics:

not specified

Species / strain 2

Species / strain / cell type:

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

Details on mammalian cell type (if applicable):

Not applicable

Additional strain / cell type characteristics:

not specified

Metabolic activation:

with and without

Metabolic activation system:

Aroclor 1254

Test concentrations with justification for top dose:

The test concentrations were: 10000, 3333, 1000, 333, 100 µg/plate.

Vehicle / solvent:

Water

Controls

Controls 1

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Remarks:

DMSO, except sodium azide (sterile, deionized water)

True negative controls:

yes

Positive controls:

yes

Controls 2

Positive controls:

yes

Positive control substance:

2-nitrofluorene

Remarks:

For the S. typhimurium TA98, TA1538 without metabolic activation

Controls 3

Positive controls:

yes

Positive control substance:

sodium azide

Remarks:

For the S. typhimurium TA100 and TA1535 without metabolic activation.

Controls 4

Positive controls:

yes

Positive control substance:

9-aminoacridine

Remarks:

For the S. typhimurium TA1537 without metabolic activation.

Controls 5

Positive controls:

yes

Positive control substance:

other: 2-aminoanthracene

Remarks:

For the S. typhimurium TA98, TA100, TA1535, TA 1537, TA 1538 with metabolic activation.

Details on test system and experimental conditions:

Five doses of the test article were plated with all five tester strains (TA98, TA100, TA 1535, TA1537, TA1538) with and without metabolic activation. All solvent controls and test article doses were plated in triplicate. Without metabolic activation, 100 µL of tester strain and 50 µL of solvent or test article and 0.5 of S-9 mix were added to 2.0 mL of molten selective top agar at 45 ± 2 °C. After vortexing, the mixture was overlayed onto the surface of 25 mL of minimal bottom agar. After the overlay had solidified, the plates were inverted and incubated for 48 - 72 hours at 37 ± 3 °C. Plates which were not counted immediately following the incubation period were stored at 4 ± 2 °C until such time that colony counting could be conducted.

Evaluation criteria:

Evaluation of mutagenicity assay data:
For a test article to be considered positive, it must cause at least a doubling in the mean number of revertants per plate of at least one strain. This increase in the mean number of revertants per plate must be accompanied by a dose response to increasing concentrations of the test article. In those cases where the observed dose response increase in TA1537 revertants per plate is less than three-fold, the response must be reproducible.

Statistics:

Mean values and standard deviation were calculated.

Results and discussion

Test results

Test results 1

Key result

Species / strain:

S. typhimurium TA 1538

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

True negative controls validity:

valid

Positive controls validity:

valid

Test results 2

Key result

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

True negative controls validity:

valid

Positive controls validity:

valid

Test results 3

Key result

Species / strain:

S. typhimurium TA 1537

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

True negative controls validity:

valid

Positive controls validity:

valid

Test results 4

Key result

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

True negative controls validity:

valid

Positive controls validity:

valid

Test results 5

Key result

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

True negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

Two independent mutagenicity assays were performed.

Remarks on result:

other: all strains/cell types tested

Applicant's summary and conclusion

Conclusions:

Under the study experimental conditions, disodium persulfate did not cause a positive response in any of tester strains with or without metabolic activation. Therefore, disodium persulfate was considered non-mutagenic in this bacterial reverse mutation assay.

Executive summary:

The purpose of the study was to establish the potential of disodium persulfate to induce gene mutations in Salmonella typhimurium: TA98, TA100, TA1535, TA1537 and TA1538, using Salmonella/Mammalian-Microsome plate incorporation mutagenicity Assay (Ames test), performed according to FIFRA Guideline 84 -1. Disodium persulfate was tested at five dose levels ranging from 100 to 10000 µg/plate. The dose levels were based on a preliminary toxicity test. The assay was conducted in the presence and absence of metabolic activation by Aroclor 1254 induced rat liver microsomes (S9 Mix). Revertant colonies were counted. During the tests positive and negative controls were run concurrently. The reference mutagens (sodium azide, 9 -aminoacridine, 2 -nitrofluorene, 2 -anthramine) showed a distinct increase of induced relevant colonies. Results with the test substance showed that disodium persulfate did not cause a positive response in any of the tester strains with or without metabolic activation. Therefore, disodium persulfate was considered non-mutagenic in this bacterial reverse mutation assay.