2-ethoxybenzoic acid

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Justification for type of information:

Data is from peer reviewed publication

Data source

Reference

Reference Type:

publication

Title:

Salmonella Mutagenicity Tests: IV. Results From the Testing of 300 Chemicals

Author:

Errol Zeiger

Year:

1988

Bibliographic source:

Environmental and Molecular Mutagenesis

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: Refer below principle

Principles of method if other than guideline:

Gene mutation toxicity study was performed to determine the mutagenic nature of Test chemical.

GLP compliance:

not specified

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

O-acetylsalicylic acid

EC Number:

200-064-1

EC Name:

O-acetylsalicylic acid

Cas Number:

50-78-2

Molecular formula:

C9H8O4

IUPAC Name:

Acetylsalicylic acid

Details on test material:

Name of test material (as cited in study report): O-acetylsalicylic acid
- Substance type: Organic
- Physical state: Solid

Method

Target gene:

Histidine

Species / strain

Species / strain / cell type:

S. typhimurium, other: TA97, TA98, TA100, TA1535

Details on mammalian cell type (if applicable):

Not applicable

Additional strain / cell type characteristics:

not specified

Cytokinesis block (if used):

No data

Metabolic activation:

with and without

Metabolic activation system:

The S-9 (9000g supernatant) fractions was prepared from Aroclor 1254-induced, male Sprague- Dawley rat and male Syrian hamster livers

Test concentrations with justification for top dose:

0, 1.0, 3.0, 10.0, 33.0, 100.0 or 333.0 µg/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: DMSO
- Justification for choice of solvent/vehicle: The chemical was soluble in DMSO

Controls

Untreated negative controls:

not specified

Negative solvent / vehicle controls:

yes

Remarks:

DMSO

True negative controls:

not specified

Positive controls:

yes

Positive control substance:

9-aminoacridine

sodium azide

other: 4-nitro-o-phenylenediamine (TA98 + Without S9); 2-aminoanthracene (all strains + with S9)

Details on test system and experimental conditions:

METHOD OF APPLICATION: preincubation

DURATION
- Preincubation period: 20 min
- Exposure duration: 48 hrs
- Expression time (cells in growth medium): 48 hrs
- Selection time (if incubation with a selection agent): No data
- Fixation time (start of exposure up to fixation or harvest of cells): No data

SELECTION AGENT (mutation assays): No data
SPINDLE INHIBITOR (cytogenetic assays): No data
STAIN (for cytogenetic assays): No data

NUMBER OF REPLICATIONS: At least five doses were tested in triplicate

NUMBER OF CELLS EVALUATED: No data

DETERMINATION OF CYTOTOXICITY
- Method: mitotic index; cloning efficiency; relative total growth; other: No data

OTHER EXAMINATIONS:
- Determination of polyploidy: No data
- Determination of endoreplication: No data
- Other: No data

OTHER: No data

Rationale for test conditions:

No data

Evaluation criteria:

Evaluations were made at both the individual trial and overall chemical levels. Individual trials were judged mutagenic (+), weakly mutagenic (+ W), questionable (?), or nonmutagenic (-), depending on the magnitude of the increase of his+ revertants, and the shape of the dose-response. A trial was considered questionable
(?) if the dose-response was judged insufficiently high to support a call of “ +W,” if only a single dose was elevated over the control, or if the increase seen was not dose related. The distinctions between a questionable mutagenic response and a non-mutagenic or weak mutagenic response, and between a weak mutagenic response and mutagenic response are highly subjective. It was not necessary for a response to reach two-fold over background for a chemical to be judged mutagenic.

A chemical was judged mutagenic (+) or weakly mutagenic (+ W) if it produced a reproducible dose-related response over the solvent control in replicate trials. A chemical was judged questionable (?) if the results of individual trials were not reproducible, if increases in his+ revertants did not meet the criteria for a “+W” response, or if only single doses produced increases in his+ revertants in repeat trials. Chemicals were judged nonmutagenic (-) if they did not meet the criteria for a mutagenic or questionable response.

Statistics:

Mean and SEM

Results and discussion

Test results

Species / strain:

S. typhimurium, other: TA97, TA98, TA100, TA1535

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

valid

Untreated negative controls validity:

not specified

Positive controls validity:

valid

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS
- Effects of pH: No data
- Effects of osmolality: No data
- Evaporation from medium: No data
- Water solubility: No data
- Precipitation: No data
- Other confounding effects: No data

RANGE-FINDING/SCREENING STUDIES: The chemical was tested initially in a toxicity assay to determine the appropriate dose range for the mutagenicity assay. The toxicity assay was performed using TA100 or the sytem developed by Waleh et al. Toxic concentrations were those that produced a decrease in the number of his+ colonies, or a clearing in the density of the background lawn, or both.

COMPARISON WITH HISTORICAL CONTROL DATA: No data

ADDITIONAL INFORMATION ON CYTOTOXICITY: No data

Remarks on result:

other: No mutagenic potential

Applicant's summary and conclusion

Conclusions:

Test chemical failed to induce mutation in Salmonella typhimurium strains TA97, TA98, TA100, TA1535 both in the presence and absence of S9 metabolic activation system and hence does not classify for gene mutation in vitro.

Executive summary:

Gene mutation toxicity study was performed to determine the mutagenic nature of test substance. Preincubation assay was performed as a dose level of 0, 1.0, 3.0, 10.0, 33.0, 100.0 or 333.0 µg/plate with and without S9 metabolic activation system. The chemical as dissolved in DMSO and concurrent solvent and positive controls were included in the study. Test chemical failed to induce mutation in Salmonella typhimurium strains TA97, TA98, TA100, TA1535 both in the presence and absence of S9 metabolic activation system and hence does not classify for gene mutation in vitro.