(butylamine)[[2,2'-thiobis[4-(1,1,3,3-tetramethylbutyl)phenolato]](2-)-O,O',S]nickel

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Remarks:

Read-across, Original study in Japanese

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1995

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: Guidelines for Screening Mutagenicity Testing of Chemicals (Japan) and OECD (471 and 472)

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

6,6'-di-tert-butyl-4,4'-thiodi-m-cresol

EC Number:

202-525-2

EC Name:

6,6'-di-tert-butyl-4,4'-thiodi-m-cresol

Cas Number:

96-69-5

Molecular formula:

C22H30O2S

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Sumitomo Chemical Co., Ltd; 40701
- Purity: >98%

Method

Species / strain

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2

Metabolic activation:

with and without

Metabolic activation system:

Phenobarbital and 5,6-benzoflavone-induced rat liver S9

Test concentrations with justification for top dose:

Dose-range finding: 0, 50, 150, 500, 1500, 5000 µg/plate.

Main tests:
-S9 mix, 0, 0.781, 1.56, 3.13, 6.25, 12.5, 25 and 50 μg/plate (TA100, TA1535 and TA1537), 0, 3.13 - 200 μg/plate (TA98) and 0, 313 - 5000 μg/plate (WP2)

+S9 mix, 0, 12.5, 25, 50, 100, 200, 400 and 800 μg/plate (TA100, TA1535, TA98 and TA1537) and 0, 313 - 5000 μg/plate (WP2)

Vehicle / solvent:

DMSO

Controls

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

Remarks:

DMSO

True negative controls:

no

Positive controls:

yes

Remarks:

-S9 mix: 2-(2-Furyl)-3-(5-nitro-2-furyl)acrylamide (TA100, WP2, TA98), Sodium azide (TA1535)and 9-Aminoacridine (TA1537); +S9 mix, 2-Aminoanthracene (five strains)

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar (plate incorporation)

DURATION
- Exposure duration: 48 hours

NUMBER OF REPLICATIONS: 2

Evaluation criteria:

A concentration-related increase over the range tested and/or a reproducible increase at one or more concentrations in the number of revertant colonies per plate in at least one strain with or without metabolic activation system.

Results and discussion

Test results

Test results 1

Species / strain:

other: S. typhimurium TA98, TA100, TA1535, TA1537

Metabolic activation:

without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

>12.5 μg/plate

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Test results 2

Species / strain:

other: S. typhimurium TA98, TA100, TA1535, TA1537

Metabolic activation:

with

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

>400 μg/plate

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Test results 3

Species / strain:

E. coli WP2

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity nor precipitates, but tested up to recommended limit concentrations

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS
- Precipitation: In main test 1, precipitate was observed at 50μg/plate -S9 and at 400μg/plate +S9 in all S. typhimurium strains. Precipitate was observed at all concentrations in the E. coli strain.

In main test 2, precipitate was observed at 50μg/plate -S9 and at 200μg/plate +S9 in all S. typhimurium strains. Precipitate was observed at all concentrations in the E. coli strain.

Applicant's summary and conclusion

Conclusions:

Under the conditions described for this study, it is concluded that TBBC is non-mutagenic in Salmonella typhimurium TA100, TA1535, TA98, TA1537 and Escherichia coli WP2 uvrA.

Executive summary:

In a reverse gene mutation assay in bacteria, strains of Salmonella typhimurium TA100, TA1535, TA98, TA1537 and Escherichia coli WP2 uvrA were exposed to TBBC (>98%) in DMSO at concentrations of 0, 0.781, 1.56, 3.13, 6.25, 12.5, 25 and 50 μg/plate (TA100, TA1535 and TA1537), 0, 3.13 - 200 μg/plate (TA98) and 0, 313 - 5000 μg/plate (WP2) and 0, 12.5, 25, 50, 100, 200, 400 and 800 μg/plate (TA100, TA1535, TA98 and TA1537) and 0, 313 - 5000 μg/plate (WP2) in the absence and presence of mammalian metabolic activation respectively (Phenobarbital and 5,6-benzoflavone-induced rat liver S9).

Toxicity was observed at 12.5 μg/plate (TA100 and TA1537), 25 μg/plate (TA1535) and 100 μg/plate (TA98) without S9 mix, and 400 μg/plate (TA100, TA1535 and TA1537) and 500 μg/plate (TA98) with S9 mix. No toxicity was observed in WP2 either without S9 mix or with S9 mix. The positive controls induced the appropriate responses in the corresponding strains. There was no evidence of induced mutant colonies over background.

This study is classified as acceptable. This study satisfies the requirement for Test Guideline OECD 471 for in vitro mutagenicity (bacterial reverse gene mutation) data.