Benzenesulfonic acid, 4-(1-methylethyl)-, potassium salt (1:1)

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

other: Read across from another member of the category

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2019

Report date:

2020

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

no

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Sodium p-cumenesulphonate

EC Number:

239-854-6

EC Name:

Sodium p-cumenesulphonate

Cas Number:

15763-76-5

Molecular formula:

C9H12O3S.Na

IUPAC Name:

sodium 4-isopropylbenzenesulfonate

Method

Species / strain

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2

Remarks:

Permanent stocks of these strains are kept at -80°C in ERBC facilities.

Metabolic activation:

with and without

Metabolic activation system:

Two batches of S9 tissue fraction, provided by Trinova Biochem GmbH, were used in this study and had the following characteristics:
Species Rat
Strain Sprague Dawley
Tissue Liver
Inducing Agents Phenobarbital – 5,6-Benzoflavone
Producer MOLTOX,Molecular Toxicology, Inc.
Batch Number 4009 (Toxicity test) and 4086 (Main Assays)

The mixture of S9 tissue fraction and cofactors (S9 mix) was prepared as follows (for each 10 mL):
S9 tissue fraction 1.0mL
NADP (100 mM) 0.4mL
G-6-P (100 mM) 0.5mL
KCl (330 mM) 1.0mL
MgCl2 (100 mM) 0.8mL
Phosphate buffer (pH 7.4, 200 mM) 5.0mL
DistilledWater 1.3mL

Test concentrations with justification for top dose:

Toxicity test: 5000, 1580, 500, 158 and 5 µg/plate
I and II Main assay: 5.00, 2.50, 1.25, 0.625 and 0.313 μL/plate (no effect obsterved in the first main test and the same doses were used for the second main test)

Vehicle / solvent:

Water for injection

Controls

Controls 1

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Positive controls:

yes

Positive control substance:

9-aminoacridine

Remarks:

TA1537 without metabolic activation

Controls 2

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Positive controls:

yes

Positive control substance:

sodium azide

Remarks:

TA1535 and TA100 wihtout metabolic activation

Controls 3

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Positive controls:

yes

Positive control substance:

2-nitrofluorene

Remarks:

TA98 without metabolic activation

Controls 4

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Positive controls:

yes

Positive control substance:

methylmethanesulfonate

Remarks:

E.Coli WP2 uvrA wihtout metabolic activation

Controls 5

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Positive controls:

yes

Positive control substance:

other: 2-aminoanthracene

Remarks:

All strains with metabolic activation

Details on test system and experimental conditions:

Solubility of the test item was evaluated in a preliminary trial using sterile water for injection. This solvent was selected since it is compatible with the survival of the bacteria and the S9 metabolic activity. A slightly opaque solution without any precipitation, suitable for treatment and serial dilutions, was obtained at 126 μL/mL corresponding to 50.0 μL/mL (expressed as active
ingredient). This result permitted a maximum concentration of 5.00 μL/plate to be used in the toxicity test.

The Main Assay I was performed using a plate-incorporation method. The components of the assay (the tester strain bacteria, the test item and S9 mix or phosphate buffer) were added to molten overlay agar and vortexed. The mixture was then poured onto the surface of a minimal medium agar plate and allowed to solidify prior to incubation.

The overlay mixture was composed as follows:
Overlay agar (held at 45°C) 2.0mL
Test or control item solution 0.1mL
S9 mix or phosphate buffer (pH 7.4, 0.1 M) 0.5mL
Bacterial suspension 0.1mL

The Main Assay II was performed using a pre-incubation method. The components were added in turn to an empty test-tube:
Bacterial suspension 0.1mL
Test item solution 0.1mL
or control item solution 0.05mL
S9 mix or phosphate buffer (pH 7.4, 0.1 M) 0.5mL

The incubate was vortexed and placed at 37°C for 30 minutes. Two mL of overlay agar was then added and the mixture vortexed again and poured onto the surface of a minimal
medium agar plate and allowed to solidify.

The prepared plates were inverted and incubated for approximately 72 hours at 37°C. After this period of incubation, plates were held at 4°C for 24 hours before scoring.

Permanent stocks of tested strains are kept at -80°C in ERBC.Overnight subcultures of these stocks were prepared for each day’s work. Bacteria were taken from vials of frozen cultures,
which had been checked for the presence of the appropriate genetic markers.

Evaluation criteria:

Four strains of Salmonella typhimurium (TA1535, TA1537, TA98 and TA100) and a strain of Escherichia coli (WP2 uvrA) were used in this study.
TA1535 and TA100 are predominantly sensitive to base pair mutagens, TA1537 and TA98 are sensitive to frameshift mutagens. In addition to amutation in the histidine operon, the Salmonella tester strains contain additional mutations which enhance their sensitivity to some mutagenic compounds. The rfa wall mutation results in the loss of one of the enzymes responsible for the synthesis of part of the lipopolysaccharide barrier that forms the surface of the bacterial cell wall and increases permeability to certain classes of chemicals. All strains are deficient in a DNA excision repair system (uvrB mutation) which enhances the sensitivity to some mutagens. TA98 and TA100 strains contain the pKM101 plasmid which activates an error prone DNA repair system.
Tester strain WP2 uvrA is reverted fromtryptophan dependence (auxotrophy) to tryptophan independence (prototrophy) by base substitution mutagens. In addition to the mutation in the tryptophan operon, the tester strain contains an uvrA DNA repair deficiency which enhances its sensitivity to some mutagenic compounds.

The assay was considered valid if the following criteria were met:
1. Mean plate counts for untreated and positive control plates should fall within 2 standard deviations of the current historical mean values.
2. The estimated numbers of viable bacteria/plate should fall in the range of 100 – 500 millions for each strain.
3. No more than 5% of the plates should be lost through contamination or other unforeseen event.

For the test item to be considered mutagenic, two-fold (or more) increases in mean revertant numbers must be observed at two consecutive dose levels or at the highest practicable dose level only. In addition, there must be evidence of a dose-response relationship showing increasing numbers of mutant colonies with increasing dose levels.

Statistics:

as per OECD 471 guideline

Results and discussion

Test results

Test results 1

Species / strain:

S. typhimurium TA 1537

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 2

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 3

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 4

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 5

Species / strain:

E. coli WP2 uvr A

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

Preliminary toxicity test:
No precipitation of the test item was observed at the end of the incubation period at any concentration tested, in the absence or presence of S9 metabolic activation. Neither toxicity, nor relevant increases in revertant numbers were observed with any tester strain at any dose level, in the absence or presence of S9 metabolism.

Main assay: No precipitation of the test item was observed at the end of the incubation period at any concentration in any experiment.
Neither toxicity, nor relevant increase in the number of revertant colonies was observed in the pre-incubation assay, at any dose level, with any tester strain, in the absence or presence of S9 metabolism.

Controls: Results show that mean plate counts for untreated and positive control plates fell within the normal range based on historical control data.

Controls of S9:
The sterility of the S9 mix and of the test item solutions was confirmed by the absence of colonies on additional agar plates spread separately with these solutions. Marked increases in revertant numbers were obtained in these tests following treatment with the positive control items, indicating that the assay system was functioning correctly.

Any other information on results incl. tables

Citoxicity and mutagenicity results are given in the following tables

BBL: Bacterial background lawn

A3692: Cytotoxicity - plate incorporation test without metabolic activation
Test item (μL per plate)	TA98	TA100	TA1535	TA1537	E.Coli wp2 UVRa	Bacteriotoxic effect	Cytotoxicity
Untreated	29	131	14	18	29	not evaluated	no cytotoxicity
0.0500	36	126	18	16	31	BBL: normal	no cytotoxicity
0.158	33	115	18	15	26	BBL: normal	no cytotoxicity
0.500	27	120	14	17	24	BBL: normal	no cytotoxicity
1.58	30	118	16	18	27	BBL: normal	no cytotoxicity
5.00	31	110	14	14	24	BBL: normal	no cytotoxicity
Rt/Rc 50	1,24	0,96	1,29	0,89	1,07
Rt/Rc 158	1,14	0,88	1,29	0,83	0,90
Rt/Rc 500	0,93	0,92	1,00	0,94	0,83
Rt/Rc 1580	1,03	0,90	1,14	1,00	0,93
Rt/Rc 5000	1,07	0,84	1,00	0,78	0,83
A3692: Cytotoxicity - plate incorporation test with metabolic activation
Test item (μL per plate)	TA98	TA100	TA1535	TA1537	E.Coli wp2 UVRa	Bacteriotoxic effect	Cytotoxicity
Untreated	32	135	16	24	35	not evaluated	no cytotoxicity
0.0500	28	118	14	22	36	BBL: normal	no cytotoxicity
0.158	28	120	19	21	40	BBL: normal	no cytotoxicity
0.500	26	134	13	23	36	BBL: normal	no cytotoxicity
1.58	30	127	15	19	38	BBL: normal	no cytotoxicity
5.00	26	126	20	22	34	BBL: normal	no cytotoxicity
Rt/Rc 50	0,88	0,87	0,88	0,92	1,03
Rt/Rc 158	0,88	0,89	1,19	0,88	1,14
Rt/Rc 500	0,81	0,99	0,81	0,96	1,03
Rt/Rc 1580	0,94	0,94	0,94	0,79	1,09
Rt/Rc 5000	0,81	0,93	1,25	0,92	0,97

A3692: Μutagenicity Experiment I - plate incorporation test - Strain: S. typhimurium TA 98
without metabolic activation									with metabolic activation								Conclusion
Test item (μL per plate)	Revertants per plate			mean	s.e.	Rt/Rc	Bacteriotoxic effect	Cytotoxicity	Revertants per plate			mean	s.e.	Rt/Rc	Bacteriotoxic effect	Cytotoxicity
Untreated	28	33	32	31	1,5	-	not evaluated	no cytotoxicity	37	35	38	37	0,9	-	not evaluated	no cytotoxicity	valid
0.313	31	31	34	32	1	1,03	BBL: normal	no cytotoxicity	36	40	35	37	1,5	1,00	BBL: normal	no cytotoxicity	not mutagenic
0.625	32	31	30	31	0,6	1,00	BBL: normal	no cytotoxicity	36	37	38	37	0,6	1,00	BBL: normal	no cytotoxicity
1.25	27	28	30	28	0,9	0,90	BBL: normal	no cytotoxicity	45	37	36	39	2,8	1,05	BBL: normal	no cytotoxicity
2.50	29	28	35	31	2,2	1,00	BBL: normal	no cytotoxicity	34	32	41	36	2,7	0,97	BBL: normal	no cytotoxicity
5.00	32	35	30	32	1,5	1,03	BBL: normal	no cytotoxicity	37	40	35	37	1,5	1,00	BBL: normal	no cytotoxicity
2-Nitrofluorene/2-AA	118	161	154	144	13,3	5,76			312	289	346	316	16,6	8,32			valid
DMSO	26	26	24	25	0,7	-			36	39	39	38	1,0	-			valid
A3692: Μutagenicity Experiment I - plate incorporation test - Strain: S. typhimurium TA 100
without metabolic activation									with metabolic activation								Conclusion
Test item (μL per plate)	Revertants per plate			mean	s.e.	Rt/Rc	Bacteriotoxic effect	Cytotoxicity	Revertants per plate			mean	s.e.	Rt/Rc	Bacteriotoxic effect	Cytotoxicity
Untreated	123	116	123	121	2,3	-	not evaluated	no cytotoxicity	136	129	125	130	3,2	-	not evaluated	no cytotoxicity	valid
0.313	132	118	120	123	4,4	1,02	BBL: normal	no cytotoxicity	138	122	133	131	4,7	1,01	BBL: normal	no cytotoxicity	not mutagenic
0.625	118	124	124	122	2,0	1,01	BBL: normal	no cytotoxicity	147	152	136	145	4,7	1,12	BBL: normal	no cytotoxicity
1.25	115	117	118	117	0,9	0,97	BBL: normal	no cytotoxicity	134	141	135	137	2,2	1,05	BBL: normal	no cytotoxicity
2.50	115	113	118	115	1,5	0,95	BBL: normal	no cytotoxicity	140	129	131	133	3,4	1,02	BBL: normal	no cytotoxicity
5.00	116	113	117	115	1,2	0,95	BBL: normal	no cytotoxicity	124	123	120	122	1,2	0,94	BBL: normal	no cytotoxicity
AS/2AA	516	639	688	614	51,2	5,07			1422	1116	1284	1274	88,5	10,27			valid
DMSO						-			133	118	120	124	4,7	-			valid
A3692: Μutagenicity Experiment I - plate incorporation test - Strain: S. typhimurium TA 1535
without metabolic activation									with metabolic activation								Conclusion
Test item (μL per plate)	Revertants per plate			mean	s.e.	Rt/Rc	Bacteriotoxic effect	Cytotoxicity	Revertants per plate			mean	s.e.	Rt/Rc	Bacteriotoxic effect	Cytotoxicity
Untreated	14	13	15	14	0,6	-	not evaluated	no cytotoxicity	16	13	18	16	1,5	-	not evaluated	no cytotoxicity	valid
0.313	17	15	17	16	0,7	1,14	BBL: normal	no cytotoxicity	15	16	15	15	0,3	0,94	BBL: normal	no cytotoxicity	not mutagenic
0.625	13	16	17	15	1,2	1,07	BBL: normal	no cytotoxicity	18	19	16	18	0,9	1,13	BBL: normal	no cytotoxicity
1.25	18	13	16	16	1,5	1,14	BBL: normal	no cytotoxicity	15	17	16	16	0,6	1,00	BBL: normal	no cytotoxicity
2.50	17	15	14	15	0,9	1,07	BBL: normal	no cytotoxicity	16	18	15	16	0,9	1,00	BBL: normal	no cytotoxicity
5.00	20	20	18	19	0,7	1,36	BBL: normal	no cytotoxicity	15	15	20	17	1,7	1,06	BBL: normal	no cytotoxicity
AS/2-AA	461	512	408	460	30	32,86			174	195	183	184	6,1	12,27			valid
DMSO						-			15	16	14	15	0,6	-			valid
A3692: Μutagenicity Experiment I - plate incorporation test - Strain: S. typhimurium TA 1537
without metabolic activation									with metabolic activation								Conclusion
Test item (μL per plate)	Revertants per plate			mean	s.e.	Rt/Rc	Bacteriotoxic effect	Cytotoxicity	Revertants per plate			mean	s.e.	Rt/Rc	Bacteriotoxic effect	Cytotoxicity
Untreated	16	14	17	16	0,9	-	not evaluated	no cytotoxicity	24	20	25	23	1,5	-	not evaluated	no cytotoxicity	valid
0.313	19	19	18	19	0,3	1,19	BBL: normal	no cytotoxicity	27	24	26	26	0,9	1,13	BBL: normal	no cytotoxicity	not mutagenic
0.625	21	21	17	20	1,3	1,25	BBL: normal	no cytotoxicity	24	21	26	24	1,5	1,04	BBL: normal	no cytotoxicity
1.25	18	17	24	20	2,2	1,25	BBL: normal	no cytotoxicity	23	26	25	25	0,9	1,09	BBL: normal	no cytotoxicity
2.50	21	18	17	19	1,2	1,19	BBL: normal	no cytotoxicity	27	21	24	24	1,7	1,04	BBL: normal	no cytotoxicity
5.00	17	23	17	19	2,0	1,19	BBL: normal	no cytotoxicity	23	26	22	24	1,2	1,04	BBL: normal	no cytotoxicity
9-AAc/2-AA	112	195	188	165	26,6	10,31			123	144	151	139	8,4	6,04			valid
DMSO	15	15	17	16	0,7	-			24	26	18	23	2,4	-			valid
A3692: Mutagenicity Experiment I - plate incorporation test - Strain: E. coli WP2 uvrA
without metabolic activation									with metabolic activation								Conclusion
Test item (μL per plate)	Revertants per plate			mean	s.e.	Rt/Rc	Bacteriotoxic effect	Cytotoxicity	Revertants per plate			mean	s.e.	Rt/Rc	Bacteriotoxic effect	Cytotoxicity
Untreated	26	25	32	28	2,2	-	not evaluated	no cytotoxicity	36	34	40	37	1,8	-	not evaluated	no cytotoxicity	valid
0.313	31	24	29	28	2,1	1,00	BBL: normal	no cytotoxicity	38	31	38	36	2,3	0,97	BBL: normal	no cytotoxicity	not mutagenic
0.625	27	24	29	27	1,5	0,96	BBL: normal	no cytotoxicity	31	32	37	33	1,9	0,89	BBL: normal	no cytotoxicity
1.25	29	29	30	29	0,3	1,04	BBL: normal	no cytotoxicity	34	35	35	35	0,3	0,95	BBL: normal	no cytotoxicity
2.50	31	31	36	33	1,7	1,18	BBL: normal	no cytotoxicity	31	37	40	36	2,6	0,97	BBL: normal	no cytotoxicity
5.00	29	30	25	28	1,5	1,00	BBL: normal	no cytotoxicity	31	34	29	31	1,5	0,84	BBL: normal	no cytotoxicity
MMS/2-AA	167	159	181	169	6,4	6,04			215	237	228	227	6,4	6,68			valid
DMSO						-			34	31	37	34	1,7	-			valid

A3692: Μutagenicity Experiment II - pre-incubation test - Strain: S. typhimurium TA 98
without metabolic activation									with metabolic activation								Conclusion
Test item (μL per plate)	Revertants per plate			mean	s.e.	Rt/Rc	Bacteriotoxic effect	Cytotoxicity	Revertants per plate			mean	s.e.	Rt/Rc	Bacteriotoxic effect	Cytotoxicity
Untreated	33	31	31	32	0,7	-	not evaluated	no cytotoxicity	39	45	39	41	2,0	-	not evaluated	no cytotoxicity	valid
0.313	34	39	34	36	1,7	1,13	BBL: normal	no cytotoxicity	40	37	40	39	1,0	0,95	BBL: normal	no cytotoxicity	not mutagenic
0.625	29	31	32	31	0,9	0,97	BBL: normal	no cytotoxicity	33	34	40	36	2,2	2,20	BBL: normal	no cytotoxicity
1.25	27	31	30	29	1,2	0,91	BBL: normal	no cytotoxicity	33	39	37	36	1,8	0,88	BBL: normal	no cytotoxicity
2.50	31	28	30	30	0,9	0,94	BBL: normal	no cytotoxicity	34	37	36	36	0,9	0,88	BBL: normal	no cytotoxicity
5.00	32	28	28	29	1,3	0,91	BBL: normal	no cytotoxicity	39	45	39	41	2	1,00	BBL: normal	no cytotoxicity
2-Nitrofluorene/2-AA	175	149	153	159	8,1	5,30			741	608	665	671	38,5	18,64			valid
DMSO	28	29	32	30	1,2	-			35	36	36	36	0,3	-			valid
A3692: Μutagenicity Experiment II - pre-incubation test - Strain: S. typhimurium TA 100
without metabolic activation									with metabolic activation								Conclusion
Test item (μL per plate)	Revertants per plate			mean	s.e.	Rt/Rc	Bacteriotoxic effect	Cytotoxicity	Revertants per plate			mean	s.e.	Rt/Rc	Bacteriotoxic effect	Cytotoxicity
Untreated	161	160	154	158	2,2	-	not evaluated	no cytotoxicity	176	179	177	177	0,9	-	not evaluated	no cytotoxicity	valid
0.313	178	170	164	171	4,1	1,08	BBL: normal	no cytotoxicity	149	133	140	141	4,6	0,80	BBL: normal	no cytotoxicity	not mutagenic
0.625	169	157	177	168	5,8	1,06	BBL: normal	no cytotoxicity	166	149	169	161	6,2	0,91	BBL: normal	no cytotoxicity
1.25	165	182	167	171	5,4	1,08	BBL: normal	no cytotoxicity	179	167	178	175	3,8	0,99	BBL: normal	no cytotoxicity
2.50	178	156	151	162	8,3	1,03	BBL: normal	no cytotoxicity	184	191	195	190	3,2	1,07	BBL: normal	no cytotoxicity
5.00	160	165	158	161	2,1	1,02	BBL: normal	no cytotoxicity	210	218	217	215	2,5	1,21	BBL: normal	no cytotoxicity
AS/2AA	532	647	612	597	34,0	3,78			1348	1122	1286	1252	67,4	7,07			valid
DMSO						-			176	180	174	177	1,8	-			valid
A3692: Μutagenicity Experiment II - pre-incubation test - Strain: S. typhimurium TA 1535
without metabolic activation									with metabolic activation								Conclusion
Test item (μL per plate)	Revertants per plate			mean	s.e.	Rt/Rc	Bacteriotoxic effect	Cytotoxicity	Revertants per plate			mean	s.e.	Rt/Rc	Bacteriotoxic effect	Cytotoxicity
Untreated	14	17	18	16	1,2	-	not evaluated	no cytotoxicity	13	16	15	15	0,9	-	not evaluated	no cytotoxicity	valid
0.313	14	18	16	16	1,2	1,00	BBL: normal	no cytotoxicity	15	14	14	14	0,3	0,93	BBL: normal	no cytotoxicity	not mutagenic
0.625	16	18	17	17	0,6	1,06	BBL: normal	no cytotoxicity	13	14	18	15	1,5	1,00	BBL: normal	no cytotoxicity
1.25	18	14	18	17	1,3	1,06	BBL: normal	no cytotoxicity	15	13	18	15	1,5	1,00	BBL: normal	no cytotoxicity
2.50	18	18	17	18	0,3	1,13	BBL: normal	no cytotoxicity	18	19	13	17	1,9	1,13	BBL: normal	no cytotoxicity
5.00	14	16	16	15	0,7	0,94	BBL: normal	no cytotoxicity	13	18	16	16	1,5	1,07	BBL: normal	no cytotoxicity
AS/2-AA	516	439	487	481	22,5	30,06			122	110	118	117	3,5	8,36			valid
DMSO									13	13	17	14	1,3	-			valid
A3692: Μutagenicity Experiment II - pre-incubation test - Strain: S. typhimurium TA 1537
without metabolic activation									with metabolic activation								Conclusion
Test item (μL per plate)	Revertants per plate			mean	s.e.	Rt/Rc	Bacteriotoxic effect	Cytotoxicity	Revertants per plate			mean	s.e.	Rt/Rc	Bacteriotoxic effect	Cytotoxicity
Untreated	16	13	18	16	1,5	-	not evaluated	no cytotoxicity	25	22	20	22	1,5	-	not evaluated	no cytotoxicity	valid
0.313	24	20	18	21	1,8	1,31	BBL: normal	no cytotoxicity	23	24	27	25	1,2	1,14	BBL: normal	no cytotoxicity	not mutagenic
0.625	23	17	14	18	2,6	1,13	BBL: normal	no cytotoxicity	20	15	18	18	1,5	0,82	BBL: normal	no cytotoxicity
1.25	18	20	18	19	0,7	1,19	BBL: normal	no cytotoxicity	24	21	18	21	1,7	0,95	BBL: normal	no cytotoxicity
2.50	23	19	15	19	2,3	1,19	BBL: normal	no cytotoxicity	27	24	21	24	1,7	1,09	BBL: normal	no cytotoxicity
5.00	17	21	14	17	2,0	1,06	BBL: normal	no cytotoxicity	23	27	24	25	1,2	1,14	BBL: normal	no cytotoxicity
9-AAc/2-AA	95	129	141	122	13,8	8,71			85	91	96	91	3,2	3,64			valid
DMSO	13	14	16	14	0,9	-			24	25	26	25	0,6	-			valid
A3692: Μutagenicity Experiment II - pre-incubation test- Strain: E. coli WP2 uvrA
without metabolic activation									with metabolic activation								Conclusion
Test item (μL per plate)	Revertants per plate			mean	s.e.	Rt/Rc	Bacteriotoxic effect	Cytotoxicity	Revertants per plate			mean	s.e.	Rt/Rc	Bacteriotoxic effect	Cytotoxicity
Untreated	30	29	28	29	0,6	-	not evaluated	no cytotoxicity	31	30	36	32	1,9	-	not evaluated	no cytotoxicity	valid
0.313	28	26	32	29	1,8	1,00	BBL: normal	no cytotoxicity	31	30	34	32	1,2	1,00	BBL: normal	no cytotoxicity	not mutagenic
0.625	29	29	25	28	1,3	0,97	BBL: normal	no cytotoxicity	29	34	30	31	1,5	0,97	BBL: normal	no cytotoxicity
1.25	23	27	23	24	1,3	0,83	BBL: normal	no cytotoxicity	38	32	29	33	2,6	1,03	BBL: normal	no cytotoxicity
2.50	26	28	29	28	0,9	0,97	BBL: normal	no cytotoxicity	38	32	32	34	2	1,06	BBL: normal	no cytotoxicity
5.00	30	29	24	28	1,9	0,97	BBL: normal	no cytotoxicity	32	37	36	35	1,5	1,09	BBL: normal	no cytotoxicity
MMS/2-AA	231	212	229	224	6,0	7,72			215	197	235	216	11	7,20			valid
DMSO									27	30	32	30	1,5	-			valid

Applicant's summary and conclusion

Conclusions:

Not mutagenic in bacteria

Executive summary:

The mutagenic potential in bacteria of Sodium p-cumenesulphonate was assessed following official guideline OECD 471, Bacterial Reverse Mutation Test. The test item does not induce reverse mutation in Salmonella typhimurium or Escherichia coli in the absence or presence of S9 metabolism, for all the tested strains under the reported experimental conditions. The test results are considered applicable for potassium p-cumenesulphonate based on the chemical similarity.