Ethyl lactate

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

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:

2018

Report date:

2018

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

GLP compliance:

yes (incl. QA statement)

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Ethyl lactate

EC Number:

202-598-0

EC Name:

Ethyl lactate

Cas Number:

97-64-3

Molecular formula:

C5H10O3

IUPAC Name:

ethyl 2-hydroxypropanoate

Test material form:

liquid

Remarks:

colorless transparent liquid

Method

Target gene:

TA97a: 4997D, TA98: 5011D, TA100: 4996D, TA102: 4982D, TA1535: 5012D

Species / strain

Species / strain / cell type:

S. typhimurium, other: TA97a, TA98, TA100, TA102 and TA1535

Metabolic activation:

with and without

Metabolic activation system:

S9 mix

Test concentrations with justification for top dose:

The following nominal concentrations were prepared for the first experiment:
5 µL/plate, 1.5 µL/plate, 0.5 µL/plate, 0.15 µL/plate and 0.05 µL/plate

The following nominal concentrations were prepared for the second experiment:
5 µL/plate, 2.5 µL/plate, 1.25 µL/plate, 0.63 µL/plate, 0.31 µL/plate and 0.16 µL/plate

Vehicle / solvent:

ddH2O was used as solvent to dissolve the test substance.

Controls

Untreated negative controls:

yes

Remarks:

ddH2O and DMSO were used

Positive controls:

yes

Positive control substance:

sodium azide

benzo(a)pyrene

other: 4-Nitro-1,2-phenylene diamine, 2-Amino anthracene

Details on test system and experimental conditions:

All Salmonella typhimurium strains were obtained from TRINOVA BioChem GmbH (batch: TA97a: 4997D, TA98: 5011D, TA100: 4996D, TA102: 4982D, TA1535: 5012D) and were stored as lyophilizates in the refrigerator at 2-8 °C.
The lyophilizates were used to prepare permanent cultures which were filled into vials and stored at < - 75 °C.

Eight hours before the start of each experiment, an aliquot of a permanent culture per strain to be used was taken from the deep freezer to inoculate a culture vessel containing nutrient broth. After incubation overnight for eight hours at 37 ± 1 °C, the cultures were used in the experiment. During the test, the cultures were stored at room temperature as to prevent changes in the titre.

All vessels used are made of glass or sterilizable plastic. They were sterilized before use by autoclaving.
The following vessels were used:
• Schott-bottles, glass vials, and culture flasks for solutions and media
• Plastic petri plates
• test tubes for top-agar-bacteria-substance mix

Evaluation criteria:

All strains met the criterion of at least 109 bacteria/mL, and no inconsistencies were found in the sterility control. All determined values for the spontaneous revertants of the negative controls were in the normal range of the test laboratory. All positive controls (diagnostic mutagens) showed mutagenic effects with and without metabolic activation and were within the historical control data ranges.

Results and discussion

Test results

Test results 1

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

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

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 3

Species / strain:

S. typhimurium TA 97

Remarks:

TA97a

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

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

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 5

Species / strain:

S. typhimurium TA 102

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Applicant's summary and conclusion

Conclusions:

Based on the results of this study it is concluded that Ethyl lactate is not mutagenic in the Salmonella typhimurium strains TA97a, TA98, TA100, TA102 and TA1535 in the absence and presence of metabolic activation under the experimental conditions in this study.