# Endpoint study record: Genetic toxicity in vitro.AMES Benzenesulfonyl chloride LANXESS 41201581

UUID IUC5-96313fff-3c3a-4177-9182-64a3c5fcb43d
Dossier UUID 0
Author abowles / Harlan Laboratories Ltd. / Other / other:
Date 2012-11-28 14:05:25 GMT
Remarks



# Administrative Data
Purpose flag robust study summary Study result type experimental result Study period The experimental phase of this study was performed between 11 July 2012 and 18 September 2012 Reliability 1 (reliable without restriction) Rationale for reliability incl. deficiencies Study conducted to GLP and in compliance with agr eed protocols, with no or minor deviations from standard test guidelines and/or minor methodological def iciencies, which do no effect the quality of the relevant results. 

# Data source Reference
Reference type Author Year Title Bibliographic
source Testing laboratory Report
no. Owner company Company study no. Report date study report P W Thompson 2012 Reverse Mutation Assay “Ames Test” using Salmonella typhimurium and Escherichia coli Harlan Laboratories Ltd Shardlow Business Park Shardlow Derbyshire DE72 2GD UK 41201581 Lanxess Corporation, 111 RIDC Park West Drive, Pittsburgh, PA 15275-1112, UNITED STATES OF AMERICA 2012- 11-15



# Materials and methods Type of genotoxicity gene mutation 

## Type of study bacterial reverse mutation assay (e.g. Ames test) 

## Test guideline

Qualifier Guideline Deviations according to OECD Guideline 471 (Bacte rial Reverse Mutation Assay) no according to EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria) no according to JAPAN: Guidelines for Screeni ng Mutagenicity Testing Of Chemicals no equivalent or similar to EPA OPPTS 870.5100 - Bacterial Reverse Mutation Te st (August 1998) ( Meets the requirements of the Japanese Regulatory Authorities including MET I, MHLW and MAFF, OECD Guidelines for Testing of Chemicals No. 471 "and the USA, EPA (T SCA) OPPTS harmonised guidelines.) no



## GLP compliance yes (incl. certificate) (See Appenidx 3 attached) 

# Test materials Test material identity Identifier Identity Common name Benzenesulfonyl chloride 

## Test material formother: liquid 

## Details on test material Sponsor's identification: Benzenesulfonyl chloride Description: Clear colourless liquid Purity: 99.53% Batch number: KX120302.A Date received: 16 April 2012 Expiry date: 12 April 2013 Storage conditions: Room temperature in the dark 

# Method Target gene Histidine for Salmonella. Tryptophan for E.Coli 

## Species/strain Species/strain S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Details on mammalian cell lines (if applicable) Not applicable.

Additional strain characteristics not applicable

Metabolic activation with and without

Metabolic activation

system phenobarbitone/betanaphthoflavone induced rat liver, S9

Species/strain E. coli WP2 uvr A
Details on mammalian cell lines (if applicable) Not applicable.

Additional strain characteristics not applicable

Metabolic activation with and without

Metabolic activation

system phenobarbitone/betanaphthoflavone induced rat liver, S9



## Test concentrations Preliminary Toxicity Test; 0, 0.15, 0.5, 1.5, 5, 15, 50, 150, 500, 1500 and 5000 μg/plate. Expt 1: 1.5, 5, 15, 50, 150, 500, 1500 μg/plate. Expt 2: 0 All Salmonella strains (presence of S9-mix): 1.5, 5, 15, 50, 150, 500, 1500 μg/plate. All Salmonella strains (absence of S9-mix) Escherichia coli strain WP2uvrA ( absence and presence of S9-mix): 0.5, 1.5, 5, 15, 50, 150, 500 μg/plate.



## Vehicle
Vehicle: Acetone

Justification for choice of solvent/vehicle: The test item was noted to be miscible but unstable in dimethyl sulphoxide at 50 m g/ml (an exothermic reaction occurred) but was fully miscible in acetone at 100 mg/ml in solubility checks performed in-house. Acetone w as therefore selected as the vehicle. Followi ng solubility information provided by the Sponsor, sterile distilled water was not ev aluated as a potential vehicle in this test system. 

## Controls

Negative controls yes (Spontaneous mutation rates of TA100)Solvent / vehicle controls yes (Acetone)

True negative controls no

Positive controls yes

Positive control substance other: 2-Aminoanthracene: 1 μg/plate

Remarks With S9 mix Negative controls yes (Spontaneous mutation rates of TA1535)

Solvent /

vehicle controls yes (Acetone)

True negative controls no

Positive controls yes

Positive control substance other: 2-Aminoanthracene: 2 μg/plate

Remarks With S9 mix Negative controls yes (Spontaneous mutation rates of TA1537)

Solvent /

vehicle controls yes (Acetone)

True negative controls no

Positive controls yes

Positive control substance other: 2-Aminoanthracene: 2 μg/plate

Remarks With S9 mix Negative controls yes (Spontaneous mutation rates of WP2uvrA)

Solvent /

vehicle controls yes (Acetone)

True negative controls no

Positive controls yes

Positive control substance other: 2-Aminoanthracene: 10 μg/plate

Remarks With S9 mixNegative controls yes (Spontaneous mutation rates of TA98)

Solvent /

vehicle controls yes (Acetone)

True negative controls no

Positive controls yes

Positive control substance benzo(a)pyrene Benzo(a)pyrene: 5 μg/plate

Remarks With S9 mix Negative controls yes (Spontaneous mutation rates of TA98)

Solvent /

vehicle controls yes (Acetone)

True negative controls no

Positive controls yes

Positive control substance 4-nitroquinoline-N-oxide 4-Nitroq uinoline-1-oxide: 0.2 μg/plate

Remarks without S9 mix Negative controls yes (Spontaneous mutation rates of TA1537)

Solvent /

vehicle controls yes (Acetone)

True negative controls no

Positive controls yes

Positive control substance 9-aminoacridine 9-Ami noacridine: 80 μg/plate

Remarks without S9 mix Negative controls yes (Spontaneous mutation rates of TA100)

Solvent /

vehicle controls yes (Acetone)

True negative controls no

Positive controls yes

Positive control substance N-ethyl-N-nitro-N-nitrosoguanidine N-ethy l-N'-nitro-N-nitrosoguanidine: 3 μg/plateRemarks without S9 mix Negative controls yes (Spontaneous mutation rates of TA1535)

Solvent /

vehicle controls yes (Acetone)

True negative controls no data

Positive controls yes

Positive control substance N-ethyl-N-nitro-N-nitrosoguanidine N-ethy l-N'-nitro-N-nitrosoguanidine: 5 μg/plate

Remarks Without S9 mix Negative controls yes (Spontaneous mutation rates of WP2uvrA)

Solvent /

vehicle controls yes (Acetone)

True negative controls no data

Positive controls yes

Positive control substance N-ethyl-N-nitro-N-nitrosoguanidine N-ethy l-N'-nitro-N-nitrosoguanidine: 2 μg/plate

Remarks Without S9 mix 

## Details on test system and conditions METHODS OF APPLICATION: in agar – Experiment 1 (Plate Incorporation) - Pre-incubation period for bacterial strains: 10hrs - Exposure duration: 48-72hrs - Expression time (cells in growth medium): Not applicable - Selection time (in incubation with a selective agent): 20 minutes at 37 degrees C
NUMBER OF REPLICATIONS: Triplicate plating.

DETERMINATION OF CYTOTOXICITY -Method: plates were assessed for numbers of revertant col onies and examined for effects on the growth of the bacterial background lawn.
METHODS OF APPLICATION: in agar (pre-i ncubation) – Experiment 2 (Pre-Incubation) - Pre-incubation period for bacterial strains: 10hrs - Exposure duration: 48-72hrs - Expression time (cells in growth medium): Not applicable - Selection time (in incubation with a selective agent): 20 minutes at 37 degrees C
NUMBER OF REPLICATIONS: Triplicate plating.

DETERMINATION OF CYTOTOXICITY -Method: plates were assessed for numbers of revertant col onies and examined for effects on the growth of the bacterial background lawn. 

## Evaluation criteria Acceptance Criteria: The reverse mutation assay may be considered va lid if the following criteria are met: All bacterial strains must have demonstrated the required characteristics as determined by their respective strain checks accor ding to Ames et al (1975), Maron and Ames (1983) and Mortelmans and Zeiger (2000). All tester stra in cultures should exhibit a characteristic number of spontaneous reve rtants per plate in the vehicle and untreat ed controls. Combined historical negative a ndsolvent control ranges for 2009 and 2010 are presented in Appendix 3. All tester strain cultures should be in the range of 0.9 to 9 x 109 bacteria per ml. Diagnostic mut agens (positive control chemicals) must be in cluded to demonstrate both the intrinsic sensit ivity of the tester strains to mutagen exposure and the integrity of t he S9-mix. All of the positive control chemicals used in the st udy should induce marked increases in the frequency of revertant coloni es, both with or without metabo lic activation. The historica l ranges of the positive controls for 2009 and 2010 are presented in Appendix 3. There should be a minimum of four non-toxic test item dose levels. There should be no ev idence of excessive contamination.

Evaluation Criteria: There are several criteria for determining a positive result. An y, one, or all of the following can be used to determine the ov erall result of the study: 1. A dose-related increase in mutant frequency over the dose range tested (De Serres and Shelby (1979)). 2. A reproducible increase at one or more concentrations. 3. Biological relevance against in -house historical control ranges. 4. Statistical analysis of data as dete rmined by UKEMS (Mahon et al (1989)). 5. Fold increase greater than two times the concurrent solvent c ontrol for any tester strain (especially if accompanied by an o ut of historical range response). A test item will be considered non-mutagenic (negative) in the test system if the above criteria are not met. 

## Statistics Standard Deviation Dunnetts Linear Regression Analysis 

## Any other information on materials and methods incl. tables Tester strains

Salmonella typhimurium Strains Genotype Type of mutations indicated
TA1537 his C 3076; rfa - 

## ; uvrB - 

## : frame shift mutations TA98 his D 3052; rfa - 

## ; uvrB - 

## ;R-factor TA1535 his G 46; rfa - 

## ; uvrB - 

## : base-pair substitutions TA100 his G 46; rfa - 

## ; uvrB - 

## ;R-factor Escherichia coli Strain Genotype Type of mutations indicated
WP2 uvrA trp - 

## ; uvrA - 

## : base-pair substitution

The strains of bacteria used in the test were obtai ned from the University of California, Berkeley, on culture discs, on 04 August 1995, from Syngenta CTL, Alderley Edge, as frozen vials, on 20 March 2007 or from the British Industrial Biological Resear ch Association, on nutrient agar plates, on 17 August 1987. All of the strains were stored at approxim ately -196°C in a Statebourne liquid nitrogen freezer, model SXR 34. In this assay, overnight sub-cultures of the approp riate coded stock cultures were prepared in nutrient broth and incubated at 37oC for approximately 10 hours. Each culture was monitored spectrophotometrically for turbidity with titres deter mined by viable count analysis on nutrient agar plates. The test item was accurately weighed and approximat e half-log dilutions prepared in dimethyl sulphoxide by mixing on a vortex mixer on the day of each experin t. All formulations were used within four hours of preparation and were assumed to be stable for this period. Analysis for concentration, homogeneity and stability of the test item formulations is not a requi rent of the test guidelines and was, therefore, not determined. This is an exception with regard to GLP and has been reflected in the GLP compliance statement. The S9 Microsomal fraction was prepared in-house (01 July 2012) from rats induced with Phenobarbitone/b-Naphthoflavone at 80/100 mg/kg/day, orally, for 3 day s prior to preparation on day 4. The S9 homogenate was produced by homogenising the liver in a 0.15M KCl solution (1g liver to 3 ml KCl) followed by centrifugation at 9000 g . The protein content of the resultant supernatant was adjusted to 20 mg/ml. Aliquots of the supernatant were frozen and stored at approximately -196 o 

## C. Prior to use, each batch of S9 was tested for its capability to activate known mutagens in the Ames test.

## The S9-mix was prepared immediately before use using sterilised co-factors and maintained on ice for the duration of the test. S9: 5.0 ml 1.65 M KCl/0.4 M MgCl 2 

## : 1.0 ml 0.1 M Glucose-6-phosphate: 2.5 ml 0.1 M NADP: 2.0 ml 0.2 M Sodium phosphate buffer (pH 7.4): 25.0 ml Sterile distilled water: 14.5 ml
A 0.5 ml aliquot of S9-mix and 2 ml of molten, trac e histidine or tryptophan supplemented, top agar were overlaid onto a sterile Vogel-Bonner Minimal agar plate in order to asse ss the sterility of the S9-mix. This procedure was repeated, in triplicat e, on the day of each experiment. Top agar was prepared using 0.6% Bacto agar (lot number 1297425 09/16) and 0.5% sodium chloride with 5 ml of 1.0 mM histidine and 1.0 mM biotin or 1.0 mM tryptophan solution added to each 100 ml of top agar. Vogel-Bonner Minimal agar plates were purchased from SGL Ltd (lot numbers 32515 08/12, 32765 10/12 and 32773 10/12).
Preliminary Toxicity Test In order to select appropriate dose levels for use in the main test, a preliminary test was carried out to determine the toxicity of the test item. The concentrat ions tested were 0, 0.15, 0.5, 1.5, 5, 15, 50, 150, 500, 1500 and 5000 μg/plate. The test was performed by mixing 0.1 ml of bacterial culture (TA100 or WP2 uvrA ), 2 ml of molten, trace histidine or tryptoph an supplemented, top agar, 0.1 ml of test item formulation and 0.5 ml of S9-mix or phosphate bu ffer and overlaying onto sterile plates of Vogel-Bonner Minimal agar (30 ml/plate). Ten concentrations of the test item formulation and a vehicle control (acetone) were tested. In addition, 0.1 ml of the maximum concent ration of the test item and 2 ml of molten, trace histidine or tryptophan supplemented, top agar were over laid onto a sterile nutrient agar plate in order to assess the sterility of the test it em. After approximately 48 hours incubation at 37°C the plates were assessed for numbers of revertant colonies using a Domino colony counter and examined for effects on the growth of the bacterial background lawn.
Mutation Test – Experiment 1 Seven concentrations of the test item (1.5, 5, 15, 50, 150, 500, 1500 μg/plate) were assayed in triplicate against each tester strain, using the direct plate incorporation method. Additional dose levels and an expanded dose range were selected in order to achieve both four non-toxic dose levels and the toxic limit of the test item. Measured aliquots (0.1 ml) of one of the bacterial cultur es were dispensed into sets of test tubes followed by 2 ml of molten, trace histidine or tryptophan suppl emented, top agar, 0.1 ml of the vehicle, test item formulation or positive control and either 0.5 ml of S9-mix or phosphate buffer. The contents of each test tube were mixed and equally distri buted onto the surface of Vogel-Bonne r Minimal agar plates (one tube per plate). This procedure was repeated, in triplicate, for each bacterial strain and for each concentration of test item both with and without S9-mix. All of the plates were incubated at 37°C for appr oximately 48 hours and the fr equency of revertant colonies assessed using an automated colony counter.
Mutation Test – Experiment 2 The second experiment was performed using fresh bacter ial cultures, test item and control solutions. The dose range was amended slightly following the results of Experiment 1 as follows: All Salmonella strains (presence of S9-mix): 1.5, 5, 15, 50, 150, 500, 1500 μg/plate.

All Salmonella strains (absence of S9-mix) and Escherichia coli strain WP2 uvrA (absence and presence of S9-mix): 0.5, 1.5, 5, 15, 50, 150, 500 μg/plate. Additional dose levels and an expanded dose range were again selected in order to achieve both four non-toxic dose levels and the toxic limit of the test item. As it is good scientific practice to alter one conditi on in the replicate assay, the exposure condition was

## changed from plate incorporation to pre-incubation. Th e test item formulations and vehicle control were therefore dosed as follows: Measured aliquots (0.1 ml) of one of the bacterial cultur es were dispensed into sets of test tubes followed by 0.5 ml of S9-mix or phosphate buffer and 0.05 ml of the vehicle or test item formulation and incubated for 20 minutes at 37°C with shaking at approximately 130 rpm prior to the addition of 2 ml of molten, trace histidine or tryptophan supplemented, top agar. The contents of the tube were then mixed and equally distributed on the surface of Vogel-Bonner Minimal aga r plates (one tube per plate). This procedure was repeated, in triplicate, for each bacterial strain and for each concentration of test item both with and without S9-mix. The positive and untreated controls we re dosed using the standard plate incorporation method described in Experiment 1. All of the plates were incubated at 37°C for appr oximately 48 hours and the fr equency of revertant colonies assessed using an automated colony counter. 

# Results and discussions Test results Species/strain E. coli WP2 uvr A
Metabolic activation with and without

Test system all strains/cell types tested Genotoxicity negative Cytotoxicity yes (The test item caused a visible reduction in the growth of the bacterial background lawns of all of the tester strains, initially from 150 and 500 μg/plate in the absence and presence of S9 -mix respectively.)
Vehicle controls valid yes

Negative controls valid yes

Positive controls valid yes

Species/strain S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Metabolic activation with and without

Test system all strains/cell types tested Genotoxicity negative Cytotoxicity yes (The test item caused a visible reduction in the growth of the bacterial background lawns of all of the tester strains, initially from 150 and 500 μg/plate in the absence and presence of S9 -mix respectively.)
Vehicle controls valid yes

Negative controls valid yes

Positive controls valid yes



## Additional information on results TEST-SPECFIC CONFOUNDING FACTORS: - Precipitation: No test item precipitate was observed on the pl ates at any of the doses tested in either the presence or absen ce of S9-mix.
STERILITY, VEHICLE AND POSITIVE CONTROL DATA: - Prior to use, the master strains were checked for charac teristics, viability and spontaneous reversion rate (all were found t o be satisfactory). The amino acid supplement ed top agar and S9 mix used in both experiments was shown to be sterile. The culture density for each bacterial strain was al so checked and considered acceptable. T hese data are not given in the report. Results for the negative controls (spontaneous mutation rates) ar e presented in Table 1 and were considered to be acceptable. These data are for concurrent untreated control plates performed on the same day as the Mutation Test. The individual plate counts, the mean number of revertant col onies and the standard deviations, for the test item, positive and vehicle controls, both with and without met abolic activation, are presented in Table 2 and Table 3 for Experiment 1 and Table 4 and Table 5 for Experiment 2.A history profile of vehicle/untreated and positive control va lues (reference items) for 2010 and 2011 are presented in Appendi x 2. 

## Any other information on results incl. tables RESULTS The test item was toxic at and above 500 μg/plate to both of the strains of bacteria used (TA100 and WP2 uvrA ). The test item formulation and S9-mix used in this experiment were both shown to be sterile.
The numbers of revertant colonies for the toxicity assay were:

With (+) or without (-)

S9-mix Strain Dose (μg/plate)

0 0.15 0.5 1.5 5 15 50 150 500 1500 5000

- TA100 8 4 79 79 97 91 68 84 91 0V 0V 0T

+ TA100 8 9 98 106 101 82 92 107 116 97S 0T 0T

- WP2 uvrA 2 0 22 21 27 20 34 36 26 0V 0T 0T

+ WP2 uvrA 4 4 27 35 36 38 32 31 35 0V 0T 0T S: Sparse bacterial background lawn V: Very weak bacterial background lawn T: Toxic, no bacterial background lawn

Mutation Test Table 1: Spontaneous Mutation Rate s (Concurrent N egative Control) Experiment 1 Number of revertants (mean number of colonies per plate) Base-pair substitution type Frameshift type

TA100 TA1535 WP2 uvrA TA98 TA1537

75 17 29 15 17
82 (80) 28 (20) 17 (21) 18 (15) 7 (11)

83 16 16 13 10

Experiment 2 Number of revertants (mean number of colonies per plate) Base-pair substitution type Frameshift type

TA100 TA1535 WP2 uvrA TA98 TA1537

84 13 30 19 10
94 (88) 8 (13) 20 (25) 15 (15) 9 (8)

86 18 24 10 5

FOR TABLES OF RESULTS FOR MUTATION TEST: Please see attached in overall remarks, attachments

References:

## Ames B N, McCann J and Yamasaki E (1975), Methods for detecting carcinogens and mutagens with the Salmonella /mammalian microsome mutagenicity test, Mutation Research , 31, 347-364. Maron D M and Ames B N (1983), Revised Methods for the Salmonella mutagenicity test, Mutation Research , 113, 173 - 215. Mortelmans K and Zeiger E (2000), The Ames Salmonella /microsome mutagenicity assay, Mutation Research , 455, 29-60. Green M H L and Muriel W J (1976), Mutagen Testing Using TRP + 

## Reversion in Escherichia coli
, Mutation Research , 38, 3- 32. Maron D M, Katzenellenbogen J and Ames B N (1981) , Compatibility of organic solvents with the Salmonella /Microsome Test, Mutation Research , 88, 343-350. De Serres F J and Shelby M D (1979), Recommendations on data production and analysis using the Salmonella /microsome mutagenicity assay, Environmental Mutagenesis , 1, 87-92. Mahon G A T et al (1989) Analysis of data from microbial co lony assays. In: Statistical Evaluation of Mutagenicity Test Data, UKEMS sub-committee on guide lines for mutagenicity testing (Kirkland D J Ed.), Cambridge University Press Report, 26-65. 

# Overall remarks, attachments Remarks on results including tables and figures 41201581-tables.pdf: Summary Data Tables 2-5. 41201581-CoA.pdf: A copy of the CoA (as presented in the report). 41201581-Appendix2.pdf; In-house Historical Ranges 2009-2010. 41201581-Appendix 3-GLP; GLP certificate as presented in the report 

## Attached background material
Attached document Remarks 41201581-tables.pdf / 40.61 KB (application/ pdf) Summary Data Tables 2-5 41201581-COA.pdf / 125.34 KB (application/pdf) A copy of the CoA (as presented in the report) 41201581-Appendix2.pdf / 20.35 KB (application/pdf) In-house Historical Ranges 2009-2010 41201581-Appendix3.pdf / 100.12 KB (application/pdf) GLP certificate as presented in the report 

# Applicant's summary and conclusion Interpretation of results negative 

## Conclusions The test item, Benzenesulfonyl chlori de, was considered to be non mutagenic under the conditions of this test. 

## Executive summary Introduction. The test method was designed to be compatible with the guidelines for bacterial mutagenicity testing published by the major Japanese Regulatory Authorities including METI, MHLW and MAFF, the OECD Guidelines for Testing of Chemical s No. 471 "Bacterial Reverse Mutation Test", Method B13/14 of Commission Regulati on (EC) number 440/2008 of 30 Ma y 2008 and the USA, EPA (TSCA) OPPTS harmonised guidelines 40 CFR 799.9510.

Methods. Salmonella typhimurium strains TA1535, TA1537, TA98, TA100 and Escherichia coli strain WP2 uvrA were treated with the test item, Benzenesul fonyl chloride, using both the Ames plate incorporation and pre-incubation methods at seven dos e levels, in triplicate, both with and without the addition of a rat liver homogenate metabolising system ( 10% liver S9 in standard co-factors). The dose range for the first experiment was determined in a preliminary toxicity assay and was 1.5 to 1500 μg/plate. The experiment was repeated on a separate day (pre-incubation method) using fresh cultures of the bacterial strains and fresh test item formulatio ns. The dose range was amended slightly following the results of Experiment 1 and ranged between 0.5 an d 1500 μg/plate, depending on bacterial strain type and presence or absence of S9-mix.

## Additional dose levels and an expanded dose range we re selected in both experiments in order to achieve both four non-toxic dose levels and the toxic limit of the test item.

Results. The vehicle (acetone) control plates gave count s of revertant colonies generally within the normal range. All of the positive controls used in t he test induced marked increases in the frequency of revertant colonies, both with or without metabolic ac tivation. Thus, the sensitivity of the assay and the efficacy of the S9-mix were validated.

The test item caused a visible reduction in the growth of the bacterial background lawns of all of the tester strains, initially from 150 and 500 μg/plate in the abs ence and presence of S9-mix respectively. The test item was, therefore, tested up to the toxic limit. No test item precipitate was ob served on the plates at any of the doses tested in either the presence or absence of S9-mix.

No toxicologically significant increases in the frequenc y of revertant colonies were recorded for any of the bacterial strains, with any dose of the test item, ei ther with or without metabolic activation or exposure method. Small, statistically significant increases in revertant colony frequency were observed in several tester strains in both the absence and presence of S9 -mix at sub toxic dose levels in Experiment 1. These increases were considered to be of no biological re levance because there was no evidence of a doseresponse relationship or reproducibility in any case. Furthermore, the individual revertant counts at the statistically significant dose levels were within the in-house historical untreat ed/vehicle control range for each tester strain and the maximum fold increase was only 1.8 times the concurrent vehicle control.

Conclusion. The test item, Benzenesulfonyl chloride, was considered to be non-mutagenic under the conditions of this test.