1-ethyl-3-methylimidazol-3-ium;acetate

Skin irritation / corrosion

Administrative data

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Data source

Reference

Reference Type:

other: Summary Report

Title:

Unnamed

Year:

2011

Report date:

2011

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 431 (In Vitro Skin Corrosion: Human Skin Model Test)

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

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

EC Number:

692-759-5

Cas Number:

1040916-84-4

Molecular formula:

C7 H13 N2 . C2 H3 O2

IUPAC Name:

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

Test material form:

liquid

Specific details on test material used for the study:

Batch: 10362/11-25-5
pH value: ca. 7 (undiluted test substance)

In vitro test system

Test system:

human skin model

Vehicle:

unchanged (no vehicle)

Details on test system:

RECONSTRUCTED HUMAN EPIDERMIS (RHE) TISSUE
- Model used: reconstructed human epidermal model EpiDerm(TM)

MTT DYE MEASUREMENT
- Wavelength: 570 nm

NUMBER OF REPLICATE TISSUES: 2 per exposure time

CONTROL TISSUES USED IN CASE OF MTT DIRECT INTERFERENCE
- no MTT interference observed

NUMBER OF INDEPENDENT EXPERIMENTS TO DERIVE FINAL PREDICTION:
two experiments: one with 3 min exposure, one with 1 h exposure

PREDICTION MODEL / DECISION CRITERIA
- The test substance is considered to be corrosive to skin if the viability after 3 minutes exposure is less than 50%, or if the viability after 3 minutes exposure is greater than or equal to 50 % and the viability after 1 hour exposure is less than 15%.
- The test substance is considered to be non-corrosive to skin if the viability after 3 minutes exposure is greater than or equal to 50% and the viability after 1 hour exposure is greater than or equal to 15%.

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

TEST MATERIAL
- Concentration: undiluted

POSITIVE CONTROL
- Concentration: 8N

Duration of treatment / exposure:

two experiments: one with 3 min exposure, one with 1 h exposure

Number of replicates:

2 per exposure time

Results and discussion

In vitro

Results

Results 1

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

3 min incubation

Value:

105

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: no indication of corrosion

Results 2

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

1 h incubation

Value:

107

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: no indication of corrosion

Other effects / acceptance of results:

Valid positive control with mean viability of 26 % after 3 min exposure and 7 % after 1 hour exposure, compared to negative control.

Any other information on results incl. tables

			Exposure: 3 min			Exposure: 1 hour
Test substance			tissue 1	tissue 2	mean	tissue 1	tissue 2	mean
NC	viable tissues	mean OD570	1.898	1.84	1.869	1.844	1.731	1.787
		viability [% of NC]	101.6	98.4	100	103.2	96.8	100
Test material		viability [% of NC]	2.016	1.922	1.969	1.984	1.825	1.905
		viability [% of NC]	107.9	102.8	105	111	102.1	107
PC	viable tissues	mean OD570	0.501	0.453	0.477	0.119	0.135	0.127
		viability [% of NC]	26.8	24.3	26	6.6	7.5	7

NC:             negative control

PC:              positive control

OD570        Optical Density [wavelength 570 nm]

Applicant's summary and conclusion

Interpretation of results:

Category 2 (irritant) based on GHS criteria

Conclusions:

Based on the observed results it was concluded, that the test material does not show a corrosive potential in the EpiDerm™ skin corrosion test under the test conditions chosen.

Executive summary:

The objective of the test was to assess the potential for corrosive activity of the test material upon first contact with skin. The assessment of the skin corrosion/irritation potential is included in international regulatory requirements for the testing of chemicals. Due to animal welfare reasons corrosivity was determined using the reconstructed human epidermal model EpiDerm.

The mean viability of two tissues per exposure time was measured after incubation of the undiluted liquid test material.

The viability was 105 % and 107% compared to the negative control after the exposure time of 3 min and 1 hour, respectively.

Valid positive control with mean viability of 26 % after 3 min exposure and 7 % after 1 hour exposure, compared to negative control.  

Based on the observed results it was concluded, that the test material does not show a corrosive potential in the EpiDerm™ skin corrosion test under the test conditions chosen. The result does not exclude an irritation potential of the test substance.

In a conservative approach, the test material might be assumed to be irritant but for a final assignment of a risk phrase at present, results from another study would be needed.