1H-Imidazolium, 1,3-diethyl-, acetate (1:1)

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Remarks:

Type of genotoxicity: gene mutation

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:

2012

Report date:

2012

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

1,3-diethyl-1H-imidazol-3-ium acetate

EC Number:

692-759-5

Cas Number:

1040916-84-4

Molecular formula:

C7 H13 N2 . C2 H3 O2

IUPAC Name:

1,3-diethyl-1H-imidazol-3-ium acetate

Method

Target gene:

S. typhimurium and E. coli

Species / strain

Species / strain / cell type:

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

Metabolic activation:

with and without

Metabolic activation system:

liver S9 mix from induced rats

Test concentrations with justification for top dose:

33 μg - 5 600 μg/plate (dose levels for Standard Plate Test and Preincubation Test)

Vehicle / solvent:

Due to the good solubility of the test substance in ultrapure water, ultrapure water was used as vehicle.

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

yes

Positive controls:

yes

Remarks:

with metabolic activation: 2-aminoanthracene; without metabolic activation: N-methyl-N'-nitro-N-nitrosoguanidine, 4-nitro-o-phenylenediamine, 9-aminoacridine and 4-nitroquinoline-N-oxide

Details on test system and experimental conditions:

Standard Plate Test
- Salmonella typhimurium
Test tubes containing 2-mL portions of soft agar (overlay agar), which consists of 100 mL agar (0.8% [w/v] agar + 0.6% [w/v] NaCl) and 10 mL amino acid solution (minimal amino acid solution for the determination of mutants: 0.5 mM histidine + 0.5 mM biotin) are kept
in a water bath at about 42 - 45°C, and the remaining components are added in the following order:
0.1 mL test solution or vehicle (negative control)
0.1 mL fresh bacterial culture
0.5 mL S9 mix (with metabolic activation)
or
0.5 mL phosphate buffer (without metabolic activation)
After mixing, the samples are poured onto Vogel-Bonner agar plates (minimal glucose agar plates) within approx. 30 seconds.
Composition of the minimal glucose agar:
980 mL ultrapure water
20 mL Vogel-Bonner E medium
15 g Difco bacto agar
20 g D-glucose, monohydrate.
After incubation at 37°C for 48 – 72 hours in the dark, the bacterial colonies (his+ revertants) are counted

- Escherichia coli
Test tubes containing 2-mL portions of soft agar (overlay agar), which consists of 100 mL agar (0.8% [w/v] agar + 0.6% [w/v] NaCl) and 10 mL amino acid solution (minimal amino acid solution for the determination of mutants: 0.5 mM tryptophan) are kept in a water bath
at about 42 - 45°C, and the remaining components are added in the following order:
0.1 mL test solution or vehicle (negative control)
0.1 mL fresh bacterial culture
0.5 mL S9 mix (with metabolic activation)
or
0.5 mL phosphate buffer (without metabolic activation)
After mixing, the samples are poured onto minimal agar plates within approx. 30 seconds.
The composition of the minimal agar (SA1 selective agar) is based on the description of Green, M.H.L. and Muriel, W.J. (5), with the exception of the amino acid solution, which has previously been added to the soft agar:
300 mL solution B (agar)
100 mL solution A (saline solution)
8 mL solution C (glucose solution)
10 mL solution D (casein solution)
After incubation at 37°C for 48 - 72 hours in the dark, the bacterial colonies (trp+ revertants) are counted.

Preincubation Test
0.1 mL test solution or vehicle, 0.1 mL bacterial suspension and 0.5 mL S9 mix (with metabolic activation) or phosphate buffer (without metabolic activation) are incubated at 37°C for the duration of about 20 minutes using a shaker. Subsequently, 2 mL of soft agar is
added and, after mixing, the samples are poured onto the agar plates within approx. 30 seconds.
After incubation at 37°C for 48 - 72 hours in the dark, the bacterial colonies are counted.

Results and discussion

Test results

Test results 1

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

other: A weak bacteriotoxic effect was observed depending on the strain and test conditions from about 2800 ug/plate onward.

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 2

Species / strain:

S. typhimurium TA 1537

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

other: A weak bacteriotoxic effect was observed depending on the strain and test conditions from about 2800 ug/plate onward.

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 3

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

other: A weak bacteriotoxic effect was observed depending on the strain and test conditions from about 2800 ug/plate onward.

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 4

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

other: A weak bacteriotoxic effect was observed depending on the strain and test conditions from about 2800 ug/plate onward.

Vehicle controls validity:

valid

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:

other: A weak bacteriotoxic effect was observed depending on the strain and test conditions from about 2800 ug/plate onward.

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

No precipitation of the test substance was found with and without S9 mix.
A weak bacteriotoxic effect was observed depending on the strain and test conditions from about 2 800 µg/plate onward.
A relevant increase in the number of his+ or trp+ revertants was not observed in the standard plate test or in the preincubation test either without S9 mix or after the addition of a metabolizing system

Applicant's summary and conclusion

Conclusions:

Thus, under the experimental conditions of this study, the test substance EEIM Acetate is not mutagenic in the Salmonella typhimurium/Escherichia coli reverse mutation assay in the absence and the presence of metabolic activation.