Polysulfides, di-tert-nonyl

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:

1997-10-31 to 1998-05-29

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: This study is classified as reliable without restriction because it was conducted according to or similar to EU B.13/14 guideline.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1998

Report Date:

1998

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to

Guideline:

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

Version / remarks:

Cited as Directive 84/449/EEC, B.14

Test guideline 2

Qualifier:

equivalent or similar to

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

GLP compliance:

yes (incl. certificate)

Remarks:

OECD GLP

Type of assay:

bacterial reverse mutation assay

Test material

Reference

Name:

Unnamed

Type:

Constituent

Details on test material:

Test compound: TPS 37
Chemical name: di-t-nonyl polysulfide
CAS no.: 68425-16-1
Source: Elf Aquitaine Production
Batch: 47978
Sulfur content: 36.9%.

Method

Target gene:

histidine

Species / strain

Species / strain / cell type:

other: Strains: TA 98, TA 100, TA 1535, TA 1537, TA 102

Metabolic activation:

with and without

Metabolic activation system:

S9 mix

Test concentrations with justification for top dose:

Experiment 1: 8, 40, 200, 1000 and 5000 µg/plate
Experiment 2: 4.883, 19.531, 78.125, 312.5, 1250 and 5000 µg/plate

Vehicle / solvent:

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

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Remarks:

DMF

True negative controls:

yes

Positive controls:

yes

Remarks:

DMSO

Details on test system and experimental conditions:

SYSTEM OF TESTING
- 2 independent trials; in the 1st and 2nd trial without metabolic activation system (MA) the direct plate incorporation method was used; this method also used in the 1st trial with MA, in the 2nd trial with MA the preincubation method (1 h, 37°C). 3 plates per concentration
- Metabolic activation system (MA): S9 fraction from liver homogenates of rats induced with 500 mg/kg Aroclor 1254
- solvent: dimethylformamide
- Controls: . solvent control (with and without MA)
. Positives controls:
- Without S9
TA98: 2-nitrofluorene 5.0 µg/plate
TA100 and TA1535: Sodium azide 2.0 µg/plate
TA1537: 9-aminoacridine 50 µg/plate
TA102: glutaraldehyde 25 µg/plate
- With S9
TA98, TA100 and TA1535: 2-aminoanthracene 5.0 µg/plate
. sterility control checked during the test.
- Concentrations:
Experiment 1: 8, 40, 200, 1000 and 5000 µg/plate
Experiment 2: 4.883, 19.531, 78.125, 312.5, 1250 and 5000 µg/plate
- Cytotoxicity: A preliminary toxicity test was performed to define the concentrations to be used for the mutagenicity study. TA100 exposed to 8-5000 µg/plate with and without MA

Evaluation criteria:

The test article was considered to be mutagenic if:
1. the assay was valid
2. a dose related and reproducible increase in the number of revertants is observed, or a significant and reproducible increase in the number of revertants was induced at one or more test concentration

Results and discussion

Test results

Species / strain:

other: Strains: TA 98, TA 100, TA 1535, TA 1537, TA 102

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

other: >= 1250 µg/plate

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

Evidence of toxicity was observed at >=1250 µg/plate in only a few test strains. Precipitation of test agent was observed on all plates treated at concentrations >= 1000  µg/plate.

The mean numbers of revertant colonies on negative control plates all fell within acceptable ranges, and were significantly elevated by positive control treatments.

No TPS 37 treatment of any of the test strains produced an increase in revertant numbers sufficient to be considered as indicative of mutagenic activity.

Remarks on result:

other: strain/cell type: Strains: TA 98, TA 100, TA 1535, TA 1537, TA 102

Remarks:

Migrated from field 'Test system'.

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative

TPS 37 did not induce mutation in five strains of Salmonella typhimurium (TA98, TA100, TA1535, TA1537 and TA102), when tested under the conditions employed for this study, which included treatments up to 5000 µg/plate, both in the absence and in the presence of a rat liver metabolic activation system (S-9).

Executive summary:

In a reverse gene mutation assay in bacteria, strains TA98, TA100, TA1535, TA1537 and TA102 of S. typhimurium were exposed to TPS 37 in DMF at concentrations of 8, 40, 200, 1000, and 5000 µg/plate in the presence and absence of mammalian metabolic activation using the Ames test.

 

TPS 37 was tested up to limit concentrations of 5000 µg/plate. Following treatment in experiment 1, evidence of toxicity was observed at the highest dose (5000 µg/plate) treatments in only a few test strains. Precipitation of test agent was observed on all plates treated at concentrations of 1000 and 5000 µg/plate. For experiment 2, dose intervals were narrowed to more closely investigate those concentrations of TPS 37 most likely to induce mutagenic response. All treatments in the presence of S-9 employed a pre-incubation step. Evidence of toxicity was found in the higher test doses in the presence and absence of S-9 mix. Precipitation of test agent was observed on all plates at concentrations of 1250 and 5000 µg/plate. No treatment with TPS 37 of any test strains produced an increase in revertant numbers high enough to be considered characteristic of mutagenic activity. TPS 37 did not induce mutation in five strains of S. typhimurium when tested under study conditions. Conditions included treatments up to 5000 µg/plate and the absence and presence of rat liver activation system.

 

This study received a Kilmisch score of 1 and is classified as reliable without restrictions because it adheres to guidelines and includes testing at the limiting concentration.