Registration Dossier

Administrative data

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:
migrated information: read-across from supporting substance (structural analogue or surrogate)
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other: GLP compliant, guideline study, available as unpublished report, minor restrictions in design (E. coli WP2 uvrA or S. typhimurium TA 102 missing) and/or reporting but otherwise adequate for assessment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:
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:
Interpretation of results (migrated information):negativeThe 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.

Justification for classification or non-classification