Ethanesulphonic acid

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2006

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2006

Report date:

2006

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

other: Ames II (Xenometrix, Boulder/USA)

Principles of method if other than guideline:

The assay was performed according to the instruction manual for the Ames II (Xenometrix,
Boulder/USA).
R97-0491 Ames BN, McCann J, Yamasaki E. Methods for detecting carcinogens and
mutagens with the salmonella/mammalian-microsome mutagenicity test. Mutat
Res 1975; 31:347-364.
R99-2379 Gee P, Sommers CH, Melick AS, Gidrol XM, Todd MD, Burris RB, et al.
Comparison of responses of base-specific Salmonella tester strains with the
traditional strains for identifying mutagens: the results of a validation study.
Mutat Res 1998; 412:115-130.
R04-0638 Flueckiger-Isler S, Baumeister M, Braun K, Gervais V, Hasler-Nguyen N,
Reimann R, et al. Assessment of the performance of the Ames II assay: a
collaborative study with 19 coded compounds. Mutat Res Genet Toxicol
Environ Mutagen 2004; 558:181-197.

GLP compliance:

no

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Ethanesulphonic acid

EC Number:

209-843-0

EC Name:

Ethanesulphonic acid

Cas Number:

594-45-6

Molecular formula:

C2H6O3S

IUPAC Name:

ethanesulfonic acid

Test material form:

liquid

Method

Species / strain

Species / strain 1

Species / strain / cell type:

S. typhimurium TA 98

Species / strain 2

Species / strain / cell type:

S. typhimurium, other: TA 7001, TA 7002, TA 7003, TA 7004, TA 7005 and TA 7006

Remarks:

TA mix

Metabolic activation:

with and without

Metabolic activation system:

microsomal liver enzymes from rats

Test concentrations with justification for top dose:

Nine concentration levels (1 to 7200 μg/mL)
The actual concentration corrected for the 70.3% purity is about 5000 μg/mL for ethanesulfonic acid.

Vehicle / solvent:

dimethylsulfoxide

Controls

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

4-nitroquinoline-N-oxide

2-nitrofluorene

other: and 2- aminoanthracene (2-AA)

Evaluation criteria:

The pH indicator bromocresol purple turns the colour of the cultures from blue to yellow as
the pH drops due to the accumulation of catabolites from the metabolic activity of revertant
cells. The number of positive wells (yellow) out of a total of 48 wells is an indication of the
frequency of reversion per replicate per dose and was compared to the number of
spontaneous revertant wells of the solvent control. Each test point contains 48 wells of a 384-
well plate. In each 48-well section, the wells were scored for the number of revertant wells
(yellow) and the mean value of the triplicates was calculated.

Statistics:

The experiment is regarded valid, if the vehicle control showed the normal spontaneous
revertant frequency and the diagnostic mutagens caused the expected increase in the mutation
rate. The individual test chemicals were classified according to the following criteria:
Negative: ≤8/48 wells
Equivocal: 9-12/48 wells
Positive: ≥13/48 wells
Historical control range: 0-7/48 wells in ca 500 experiments (1999-up to date)
A concentration-dependent increase of revertant wells (mean of triplicate) over the vehicle
control is indicative for a genotoxic activity of the test substance.

Results and discussion

Test results

Test results 1

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Test results 2

Species / strain:

S. typhimurium, other: TA mix

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Applicant's summary and conclusion

Conclusions:

Ethanesulfonic acid 70 % caused neither
base-pair substitution nor frameshift mutations in a series of S. typhimurium tester
strains (TA Mix and TA 98) in the absence and presence of a metabolic activation
system when tested up to recommended concentrations. Therefore, based on these
results the test substance can be classified as "Ames II negative".