Benzoic acid, 4-[2-[1-hydroxy-6-[[[[5-hydroxy-6-(2-phenyldiazenyl)-7-sulfo-2-naphthalenyl]amino]carbonyl]amino]-3-sulfo-2-naphthalenyl]diazenyl]-, sodium salt (1:3)

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

Based on the available test on similar substance, Direct Orange 102 could be considered as not mutagen.

Link to relevant study records

Reference

Endpoint:

in vitro gene mutation study in bacteria

Remarks:

Type of genotoxicity: gene mutation

Type of information:

other: experimental result from similar substance

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP compliant, guideline study, available as unpublished report, minor restrictions in design (E. coli WP2 uvrA or S. typhimurium TA 102 missing) and/or reporting but otherwise adequate for assessment

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

yes

Remarks:

; E.coli WP2 uvrA or S.typhimurium TA 102 missing

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Target gene:

His-locus

Species / strain / cell type:

S. typhimurium, other: TA 1535, TA 1537, TA 1538, TA 98, TA 100

Additional strain / cell type characteristics:

not applicable

Metabolic activation:

with and without

Metabolic activation system:

Aroclor 1254-induced rat liver S-9 mix

Test concentrations with justification for top dose:

8, 40, 200, 1000, 5000 µg/plate

Vehicle / solvent:

- Vehicle/solvent used: Aqua bidest.- Justification for choice of solvent/vehicle: The solvent was chosen for its solubility properties and its non-toxicity to the bacteria.

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

9-aminoacridine

2-nitrofluorene

sodium azide

other: 2-aminoanthracene

Remarks:

With metabolic activation: 2-AA (all strains); Without metabolic activation: 2-nitrofluorene (TA 98, TA 1538), sodium azide (TA 100, TA 1535), 9-aminoacridine (TA 1537)

Details on test system and experimental conditions:

- METHOD OF APPLICATION: in agar (plate incorporation)- DURATION: Exposure duration: 3 days- NUMBER OF REPLICATIONS: The assay was performed in two independent experiments, using identical procedures, both with and without metabolic activation. Each concentration was tested in triplicate. Negative and positive controls were tested in quintuplicate with and without metabolic activation.- DETERMINATION OF CYTOTOXICITY: Toxicity of the test article was determined by clearing of the bacterial background lawn.

Evaluation criteria:

The assay was considered valid if the following criteria were met:- the mean negative control counts fell within the normal range- the positive control chemicals induced clear increases in revertant numbers confirming discrimination between different strains, and an active S-9 preparation- no more than 5% of the plates were lost through contamination or some other unforseen eventA test compound was considered to be mutagenic if:- the assay was valid- two or three-fold increases (dependent on strain; two-fold in TA 98 or TA 100, three-fold in TA 1535, TA 1537, or TA 1538) in revertant numbers, were accompanied by significant F-statistics and dose-response correlations- the positive responses were reproducible

Statistics:

If the two or three-fold levels were exceeded, analysis of variance (F-test) and regression analysis were also performed.

Species / strain:

S. typhimurium, other: TA 1535, TA 1537, TA 1538, TA 98, TA 100

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 applicable

Positive controls validity:

valid

Additional information on results:

RANGE-FINDING/SCREENING STUDIES:The test article was tested for toxicity in strain TA 100, at the concentrations of 8, 40, 200, 1000 and 5000 µg/plate. Triplicate plates without and with S-9 mix were used. Negative (solvent) and positive controls were included in quintuplicate without and with S-9 mix. On examination these plates showed no evidence of toxicity to the background lawn. This dose range was therefore retained for experiment 1 treatments, and also for treatments in the second mutation experiment, at the sponsor's request. Revertant colonies were counted and these results comprise the TA 100 experiment 1 mutagenicity data.ADDITIONAL INFORMATION ON CYTOTOXICITY: No toxicity was seen in either of the mutation experiments.

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Conclusions:

The test substance is not mutagenic under these experimental conditions.

Executive summary:

The substance to be registered was tested at a concentration of 75% for its mutagenic potential, in an OECD 471 guideline study, based on the ability to induce point mutation in selected loci of several bacterial strains of Salmonella typhimurium (TA 1535, TA 1537, TA 1538 TA98, TA100) in a reverse mutation assay. No cytotoxicity was observed. An increase in the number of his+ revertants was not observed in the standard plate test either without S9 mix or after the addition of a metabolizing system. It was therefore concluded that the test substance is not mutagenic under these experimental conditions.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Additional information

Additional information from genetic toxicity in vitro:

Based on the available test on similar substance, Direct Orange 102 could be considered as not mutagen.