Trisodium bis[2-[[2,4-dihydroxy-3-[(2-methyl-4-sulphophenyl)azo]phenyl]azo]benzoato(3-)]chromate(3-)

Genetic toxicity: in vitro

Administrative data

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: read across; Guideline study, GLP, 4 strains included

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1991

Report date:

1991

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

see chapter 13

IUPAC Name:

see chapter 13

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Method

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 Syrian golden Hamster liver

Test concentrations with justification for top dose:

0-1-3,3-10-33,3-100-333-1000-5000 µg/plate

Vehicle / solvent:

water

Controls

Negative solvent / vehicle controls:

yes

Positive controls:

yes

Positive control substance:

sodium azide

congo red

other: 4-nitro-o-phenylenediamine

Details on test system and experimental conditions:

METHOD OF APPLICATION: in medium; in agar (plate incorporation); preincubation; in suspension; as impregnation on paper disk

DURATION
- Preincubation period: 30 minutes
- Exposure duration: 48 hours

NUMBER OF REPLICATIONS: 3

DETERMINATION OF CYTOTOXICITY
- Method: other:evaluation of background lawn

Evaluation criteria:

Validity criteria:
normal background lawn
normal range of spontaneous reversions in control

effect criteria:
reproducible, significant, dose related increase of reversions

Statistics:

none

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 nor precipitates, but tested up to recommended limit concentrations

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Any other information on results incl. tables

Dose µg/plate	S9-mix	TA1535	TA1535	TA1537	TA1537	TA98	TA98	TA100	TA100
Negative Control	-	9	12	4	7	32	30	105	107
Solvent Control	-	9	12	5	6	34	20	103	113
10	-	8	15	6	5	33	22	113	94
100	-	8	19	4	5	39	29	102	79
333,3	-	10	15	4	8	30	28	109	93
1000	-	8	14	6	10	28	31	112	85
5000	-	10	14	4	11	32	28	98	98
Pos Control	-	945	1080	209	240	2286	2076	973	1170
Negative Control	+	12	14	5	4	31	45	91	93
Solvent Control	+	6	12	5	5	32	43	83	100
10	+	8	15	3	3	25	46	95	97
100	+	8	12	4	3	33	42	86	94
333,3	+	6	12	5	3	36	49	114	120
1000	+	7	14	4	4	25	47	133	132
5000	+	11	16	3	7	20	22	131	129
Pos. Control	+	310	344	389	383	333	489	265	338

Applicant's summary and conclusion

Conclusions:

The test item did not induce gene mutations in 4 strains of Salmonella typhimurim with and without metabolic activation by syrian hamster liver S9.mix.

Executive summary:

A study was performed to investigate the potential of Braun HH 469 to induce gene mutations according to the pre-incubation method for azo-dyes using the salmonella typhimurium strains TA 1535, TA 1537, TA 98 and TA 100. The assay was performed in two independent experiments using identical procedures' both with and without Syrian hamster liver microsomal activation. Each concentration, including the controls, was tested in triplicate. The Test article was tested at the following concentrations: 10.0, 100.0, 333.3, 1000.0, and 5000.0 µg/plate. Toxic effects, evidenced by a reduction in the number of revertants, occurred in strain TA 98 at 5000.0 µg/ptate in the presence of metabolic activation in experiment II.

The plates incubated with the test article showed, normal background growth up to 5000.0 µg/ptate with and without S9 mix in all strains used. Up to the highest investigated dose, neither a significant and reproducible increase of the number of revertants was found in any strain as compared to the solvent control nor a concentration-dependent enhancement of the revertant number exists. The presence of liver microsomal activation did not influence these findings. Appropriate reference mutagens were used as positive controls and showed a distinct increase of induced revertant coronies.

CONCLUSTON: In conclusion, it can be stated that during the described mutagenicity test and under the experimental conditions reported, the test article did not induce point mutations by base pair changes or frameshifts in the genome of the strains used. Therefore, Braun HH 469 is considered to be non-mutagenic in this salmonella tlphimurium reverse mutation assay.