Disodium 3-[[2,2'-dimethyl-4'-[[4-[[(p-tolyl)sulphonyl]oxy]phenyl]azo][1,1'-biphenyl]-4-yl]azo]-4-hydroxynaphthalene-2,7-disulphonate

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 with acceptable restrictions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2002

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

GLP compliance:

not specified

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Acid Red 111

IUPAC Name:

Acid Red 111

Method

Species / strain

Species / strain / cell type:

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

Metabolic activation:

with and without

Metabolic activation system:

rat liver metabolic activation system (S9)

Test concentrations with justification for top dose:

Range Finder Experiment and Experiment I: 0.32, 1.6, 8, 40, 200 and 1000 µg/plate

Vehicle / solvent:

- Solvent: dimethyl formamide

Controls

Negative solvent / vehicle controls:

yes

Positive controls:

yes

Positive control substance:

9-aminoacridine

2-nitrofluorene

sodium azide

benzo(a)pyrene

other: 2-Aminoanthracene

Results and discussion

Test results

Species / strain:

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

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

top two dose treatments of TA 1537 in absence of S9

Vehicle controls validity:

valid

Positive controls validity:

valid

Additional information on results:

When the data from Experiment I were analysed at the 1 % level using Dunnett's test, a statistically signifrcant increase in revertant numbers was observed following TA 1538 treatments in the presence of S9. This increase showed little evidence of a dose-response and was therefore not considered to be indicative of test item mutagenic activity in this strain under the treatment condition. No statistically significant increases in revertant numbers were observed following any other treatments in this study.

TOXICITY
Toxicity ranging from a thinning of the background bacterial lawn to a complete killing of the test bacteria was observed following the top two dose treatments of TA 1537 in the absence of S9.
The top two dose treatment plates were counted manually because the dark colour of the test article prevented accurate automated counting.

PRECIPITATION
No precipitation of test agent was observed following any of the dose treatments in either the presence or absence of S9.

Any other information on results incl. tables

Summary of mean revertant colonies (-S9) - Experiment I

	TA 98	TA 100	TA 1535	TA 1537	TA 1538
Dimethyl formamide 100 µl	55± 9	117±15	21±4	22±5	18±4
Test item 0.32 µg/plate	57 ± 10	104±15	25±14	17±5	15±4
Test item 1.6 µg/plate	46 ± 2	106±10	19±2	17±4	18±4
Test item 8 µg/plate	50 ± 8	105±9	23±6	17±3	15±2
Test item 40 µg/plate	49 ± 7	91±25	13±6	19±9	15±4
Test item 200 µg/plate	38 ± 3 (M)	31±4 (M)	12±2 (M)	2±1 (M)	14±4 (M)
Test item 1000 µg/plate	35 ± 7 (M)	53±4 (M)	15±4 (M)	-- (T)	15±2 (M)
2-Nitrofluorene 5 µg	345 ± 36	-	-	-	147±8
Sodium azide 2 µg	-	739±6	552±25	-	-
9-Aminoacridine 50 µg	-	-	-	133±28	-

(M) Plates counted manually

Summary of mean revertant colonies (+S9) - Experiment I

	TA 98	TA 100	TA 1535	TA 1537	TA 1538
Dimethyl formamide 100 µl	62±9	116±12	21±7	19±4	21±3
Test item 0.32 µg/plate	58±8	121±6	20±5	19±2	24±7
Test item 1.6 µg/plate	66±7	119±16	22±3	18±2	29±2
Test item 8 µg/plate	56±11	102±13	24±10	18±3	27±3
Test item 40 µg/plate	61±4	111±3	20±4	15±2	33±3
Test item 200 µg/plate	41±6 (M)	118±11 (M)	16±6 (M)	14±3 (M)	25±5 (M)
Test item 1000 µg/plate	48±4 (M)	110±2 (M)	14±2 (M)	13±5 (M)	25±3 (M)
Benzo[a]pyrene 10 µg	226±45	-	-	-	-
2-Aminoanthracene 5 µ	-	2203±45	209±3	533±69	680±6

(M) Plates counted manually

Applicant's summary and conclusion

Conclusions:

The test item did not induce mutation in Salmonella typhimurium strains TA 98, TA 100, TA 1535, TA 1537 and TA 1538 under the conditions employed.

Executive summary:

Microbial metabolic activation test was conducted to assess the potential mutagenic effect of the test item, using Salmonella typhimurium TA 1535, TA 1537, TA 1538, TA 100 and TA 98 strains. Dimethyl formamide was used as solvent. The substance was tested at the concentrations of 0.32, 1.6, 8, 40, 200 and 1000 µg/plate. Adequate positive controls were also assayed.

When the data from Experiment I were analysed at the 1 % level using Dunnett's test, a statistically signifrcant increase in revertant numbers was observed following TA 1538 treatments in the presence of S9. This increase showed little evidence of a dose-response and was therefore not considered to be indicative of test item mutagenic activity in this strain under the treatment condition. No statistically significant increases in revertant numbers were observed following any other treatments in this study.

Toxicity ranging from a thinning of the background bacterial lawn to a complete killing of the test bacteria was observed following the top two dose treatments of TA 1537 in the absence of S9.

No precipitation of test agent was observed following any of the dose treatments in either the presence or absence of S9.

Conclusion

It was concluded that test item did not induce mutation in Salmonella typhimurium strains TA 98, TA 100, TA 1535, TA 1537 and TA 1538 under the conditions employed in this screening study.