Benzenesulfonic acid, 2-amino-4,5-dichloro-

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Remarks:

Type of genotoxicity: gene mutation

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline study with acceptable restriction - Neither TA 102 nor E. Coli are included in the panel of cells tested. - No data on GLP.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1990

Report date:

1990

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

yes

Remarks:

(neither TA 102 nor E. Coli are included in the panel of cells tested. Second positive control substance besides 2-AA for tests with S9 mix not included).

GLP compliance:

not specified

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

2-amino-4,5-dichlorobenzene-1-sulfonic acid

EC Number:

700-413-2

Cas Number:

6331-96-0

Molecular formula:

C6 H5 Cl2 N O3 S

IUPAC Name:

2-amino-4,5-dichlorobenzene-1-sulfonic acid

Method

Target gene:

Histidine operon

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:

Aroclor 1254 induced rat liver S-9 fraction mixed with a series of cofactors (MgCl2, KCl, Glu-6-p, NADP, phosphate buffer (NaH2PO4, Na2HPO2.2H2O)

Test concentrations with justification for top dose:

20, 100, 500, 2,500 and 5,000 µg/plate.

Vehicle / solvent:

- Vehicle: DMSO.
- Justification for choice of vehicle: no data.

Controls

Untreated negative controls:

yes

Remarks:

(sterility control)

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: (+ S-9): 2-aminoanthracene, 2-AA; (- S-9): N-methyl-N'-nitro-N-nitrosoguanidine, MNNG; 4-nitro-o-phenylene-diamine, 4-NOPD, 9 -aminoacridine chloride monohydrate.

Remarks:

10 µg 2-AA/plate (all strains); 5 µg MNNG/plate (TA 1535 and TA 100); 10 µg 4-NOPD/plate (TA 98), 100 µg 9-AA-Cl (TA 1537).

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar (plate incorporation test) (experiment 1) and pre incubation test (experiment 2).

DURATION
- Exposure duration: 48 hours at 37°C.
- Preincubation period: 20 min

NUMBER OF REPLICATIONS: 2 experiments; 3 cultures/experiment.

DETERMINATION OF CYTOTOXICITY
- Method: reduction in the number of spontaneous revertants or a clearing of the bacterial background lawn.

Evaluation criteria:

In general, a test chemical is considered positive if the following criteria are met:
- Doubling of the spontaneous mutation rate (control).
- Dose-response relationship.
- Reproducibility of the results

Statistics:

No statistical evaluation needed be performed.

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:

cytotoxicity

Remarks:

Standard plate test (TA 100 and TA 1537 only; at 5000 µg/plate only), Preincubation test (all strains; ≥ 2500 µg/plate)

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS
- Precipitation: Precipitation of the test item was observed at 5,000 µg/plate in the preincubation test and with S9 mix only.

RANGE-FINDING/SCREENING STUDIES:
- no data

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Any other information on results incl. tables

Table 1: Table of results (plate incorporation test); without metabolic activation

			TA 98		TA 100		TA 1535		TA 1537
	Concentration (µg/plate)	S9	X (n=3)	revertant factor	X (n=3)	revertant factor	X (n=3)	revertant factor	X (n=3)	revertant factor
test subst.	control	no	20		110		15		11
	20	no	21	1.1	104	0.9	18	1.2	9	0.8
	100	no	21	1.1	113	1.0	15	1.0	9	0.8
	500	no	19	1.0	101	0.9	15	1.0	11	1.0
	2,500	no	20	1.0	96	0.9	15	1.0	10	0.9
	5,000	no	23	1.2	64	0.6	12	0.8	7	0.6
	control	no	20		110		15		11
	positive control	no	931	46.6	2050	18.6	1797	119.8	517	47.0

 

Table 2: Table of results (plate incorporation test); with metabolic activation 

			TA 98		TA 100		TA 1535		TA 1537
	Concentration (µg/plate)	S9	X (n=3)	revertant factor	X (n=3)	revertant factor	X (n=3)	revertant factor	X (n=3)	revertant factor
test subst.	control	yes	36		118		15		11
	20	yes	32	0.9	126	1.1	16	1.1	16	1.5
	100	yes	34	0.9	117	1.0	17	1.1	15	1.4
	500	yes	31	0.9	113	1.0	15	1.0	14	1.3
	2,500	yes	24	0.7	113	1.0	15	1.0	11	1.0
	5,000	yes	21	0.6	124	1.1	17	1.1	11	1.0
	control	yes	36		118		15		11
	positive control	yes	1357	37.7	958	8.1	137	9.1	122	11.1

 

Table 3: Table of results (Preincubation test); without metabolic activation

			TA 98		TA 100		TA 1535		TA 1537
	Concentration (µg/plate)	S9	X (n=3)	revertant factor	X (n=3)	revertant factor	X (n=3)	revertant factor	X (n=3)	revertant factor
test subst.	control	no	21		104		14		8
	20	no	16	0.8	88	0.8	12	0.9	9	1.1
	100	no	11	0.5	83	0.8	13	0.9	6	0.8
	500	no	16	0.8	91	0.9	13	0.9	6	0.8
	2,500	no	B	-	B	-	13B	0.9	B	-
	5,000	no	0	0.0	0	0.0	0	0.0	0	0.0
	control	no	21		104		14		8
	positive control	no	893	42.5	866	8.3	982	70.1	371	46.4

 

Table 4: Table of results (Preincubation test); with metabolic activation 

			TA 98		TA 100		TA 1535		TA 1537
	Concentration (µg/plate)	S9	X (n=3)	revertant factor	X (n=3)	revertant factor	X (n=3)	revertant factor	X (n=3)	revertant factor
test subst.	control	yes	38		121		14		10
	20	yes	34	0.9	117	1.0	15	1.1	9	0.9
	100	yes	38	1.0	106	0.9	14	1.0	9	0.9
	500	yes	38	1.0	94	0.8	16	1.1	9	0.9
	2,500	yes	24	0.6	74	0.6	11	0.8	8	0.8
	5,000	yes	0Bp	0.0	28p	0.2	11p	0.8	0Bp	0.0
	control	yes	38		121		14		10
	positive control	yes	448	11.8	587	4.9	184	13.1	102	10.2

 

B: reduced His- Background

P: precipitation

 

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative