Barium bis[2-chloro-5-[(2-hydroxy-1-naphthyl)azo]toluene-4-sulphonate]

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:

oct - nov 1985

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1985

Report date:

1985

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Barium bis[2-chloro-5-[(2-hydroxy-1-naphthyl)azo]toluene-4-sulphonate]

EC Number:

225-935-3

EC Name:

Barium bis[2-chloro-5-[(2-hydroxy-1-naphthyl)azo]toluene-4-sulphonate]

Cas Number:

5160-02-1

Molecular formula:

C17H13ClN2O4S.1/2Ba

IUPAC Name:

barium(2+) bis(5-chloro-2-[(1E)-2-(2-hydroxynaphthalen-1-yl)diazen-1-yl]-4-methylbenzene-1-sulfonate)

Test material form:

solid: nanoform

Details on test material:

Test materials used in this dossier are all considered to fall under the definition of nano-materials according to the European Commission Recommendation 2011/696/EU as the synthesis and manufacturing of this pigment always yields particulate material with a fine particle size distribution.

Method

Target gene:

his

Species / strain

Species / strain / cell type:

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

Metabolic activation:

with and without

Metabolic activation system:

S9 mix from Aroclor induced rat liver and S9 mix from hamster supplemented with flavin mononucleotid

Test concentrations with justification for top dose:

0, 4, 20, 100, 500, 2500, 5000 microgramm/plate

Vehicle / solvent:

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

Controls

Negative solvent / vehicle controls:

yes

Positive controls:

yes

Positive control substance:

9-aminoacridine

2-nitrofluorene

sodium azide

benzo(a)pyrene

congo red

other: 2-Aminoanthracene (TA 98, TA 100, TA 1535, TA 1537, with S9 mix), 2-Aminoanthracene (Prival-Test: TA 100, TA 1535, TA 1537, with S9 mix), Benzidine (Prival-Test: TA 98, with S9 mix)

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar (plate incorporation), preincubation (prival test)

DURATION
- Preincubation period: 30 min
- Exposure duration: 48-72 h

NUMBER OF REPLICATIONS: 2 independent experiments of each protocol

NUMBER OF CELLS EVALUATED: all colonies (his+ revertants) were counted

DETERMINATION OF CYTOTOXICITY
- Method: relative total growth

Results and discussion

Test results

Species / strain:

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

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity, but tested up to precipitating concentrations

Vehicle controls validity:

valid

Positive controls validity:

valid

Additional information on results:

RANGE-FINDING/SCREENING STUDIES:
Preliminary toxicity tests were performed with all tester strains using two plates per dose to get information on mutagenicity and toxicity for calculation of an appropriate dose range. A reduced rate of spontaneously occuring colonies as well as visible thinning of the bacterial lawn were used as indicator for toxicity. Thinning of the bacterial lawn was controlled microscopically.

Applicant's summary and conclusion

Conclusions:

Interpretation of results:
negative

It is concluded the the test substance is not mutagenic in the absence and presence of rat S-9 Mix using the standard Ames Test procedure. Also in the preincubation method to Prival the test compound is not mutagenic in the presence of hamster liver S-9.