1H-Imidazolium, 3-ethyl-1-methyl-, 1,1,1-trifluoromethanesulfonate (1:1)

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation / corrosion

Remarks:

in vitro

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP and guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2012

Report date:

2012

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Test guideline 2

Qualifier:

according to guideline

Guideline:

OECD Guideline 439 (In Vitro Skin Irritation: Reconstructed Human Epidermis Test Method)

Test guideline 3

Qualifier:

according to guideline

Guideline:

other: Commission Regulation (EC) No 440/2008

Test guideline 4

Qualifier:

according to guideline

Guideline:

other: Commission Regulation (EC) No 761/2009

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

1-ethyl-3-methyl-1H-imidazol-3-ium trifluoromethanesulfonate

EC Number:

680-002-1

Cas Number:

145022-44-2

Molecular formula:

C6 H11 N2. C F3 O3 S

IUPAC Name:

1-ethyl-3-methyl-1H-imidazol-3-ium trifluoromethanesulfonate

Details on test material:

- Name of the test substance used in the study report: EMIM Triflat
- Test-substance No.: 09/0070-2
- pH-value: ca. 5 (undiluted test substance)
- Physical state: Liquid
- Analytical purity: The test substance has been characterized by analyses
- Lot/batch No.: Los-Nr. 0000000001
- Storage stability: The stability under storage conditions over the study period was guaranteed by the sponsor, and the sponsor holds this
responsibility

Test animals

Species:

other: three dimensional human epidermis model

Strain:

other: in vitro testing

Test system

Type of coverage:

other: in vitro testing

Vehicle:

unchanged (no vehicle)

Amount / concentration applied:

Single topical application of 50 uL (corrosion test) or 30 uL (irritation test)

Duration of treatment / exposure:

Corrosion Test:3 minutes
Irritation test: 1 hour

Number of animals:

Two EpiDerm tissue samples per application time (corrosion test)
Three EpiDerm tissue samples (irritation test)

Details on study design:

The present test is based on the experience that corrosive and irritant chemicals produce cytotoxicity in human reconstructed epidermis after a short term topical exposure. The test is designed to predict a skin corrosion or irritation potential of a chemical by using the three dimensional human epidermis model EpiDerm. After application of the test material to the stratum corneum surface of the EpiDerm tissue the induced cytotoxicity (= loss of viability) is measured by a colorimetric assay. Cytotoxicity is expressed as the reduction of mitochondrial dehydrogenase activity. The mitochondrial dehydrogenase reduces the yellow colored water-soluble 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) to the insoluble blue colored formazan. After isopropanol-extraction of the formazan from the tissues, the optical density of the extract is determined spectrophotometrically. Optical density of the extracts of test-substance treated tissues is compared to negative control values from tissues and expressed as relative tissue viability.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

other: viability compared to control

Basis:

mean

Remarks:

(of corrossion test)

Time point:

other: 3 min

Score:

77

Remarks on result:

other: Negative control set to 100%

Results 2

Irritation parameter:

other: viability compared to control

Basis:

mean

Remarks:

(of corrosion test)

Time point:

other: 1 hour

Score:

94

Remarks on result:

other: Negative control set to 100%

Results 3

Irritation parameter:

other: viability compared to control

Basis:

mean

Remarks:

(of irritation tes)

Score:

101

Remarks on result:

other: Negative control set to 100 %

Irritant / corrosive response data:

The test substance is not able to reduce MTT directly.
Corrosion test: The mean viability of the test-substance treated tissues determined after an exposure period of 3 minutes was 77%, and it was 94% after an exposure period of 1 hour.
Irritation test: The mean viability of the test-substance treated tissues determined after an exposure period of 1 hour with about 42 hours post-incubation was 101%.

Any other information on results incl. tables

Corrosion test

		Exposure: 3 min			Exposure: 1hour
Test substance		Tissue 1	Tissue 2	mean	Tissue 1	Tissue 2	mean
NC	mean OD570	1.989	2.035	2.012	2.124	2.041	2.082
	Viability  [% of NC]	96.8	101.2	100	102.0	98.0	100
09/0070 -2	mean OD570	1.520	1.587	1.553	2.013	1.898	1.955
	Viability  [% of NC]	75.5	78.9	77	96.7	91.2	94
PC	mean OD570	0.358	0.249	0.303	0.072	0.099	0.085
	Viability  [% of NC]	17.8	12.4	15	3.4	4.7	4

Irritation test

Test substance		Tissue 1	Tissue 2	Tissue 3	Mean	SD
NC	mean OD570	1.831	2.369	2.220	2.140
	Viability   [% of NC]	85.6	110.7	103.7	100	12.97
09/0070 -2	mean OD570	1.985	2.301	2.181	2.156
	Viability   [% of NC]	92.8	107.5	101.9	101	7.45
PC	mean OD570	0.064	0.067	0.059	0.064
	Viability   [% of NC]	3.0	3.1	2.8	3	0.18

 

Applicant's summary and conclusion

Conclusions:

Based on the observed results it was concluded, that EMIM Triflat does not show a skin irritation potential in the EpiDerm skin corrosion/irritation test under the test conditions chosen.

Executive summary:

The potential of EMIM Triflat to cause dermal corrosion/irritation was assessed by a single topical application of 50 μL (corrosion test) or 30 μL (irritation test) of the test substance to a reconstructed three dimensional human epidermis model (EpiDerm™).

For the corrosion test two EpiDerm™ tissue samples were incubated with the test substance for 3 minutes and 1 hour, respectively. The irritation test was performed with three EpiDerm™ tissue samples, which were incubated with the test substance for 1 hour followed by a 42-hours post-incubation period. Tissue destruction was determined by measuring the metabolic activity of the tissue after exposure/post-incubation using a colorimetric test. The reduction of mitochondrial dehydrogenase activity, measured by reduced formazan production after incubation with a tetrazolium salt (MTT) was chosen as endpoint. The formazan production of the testsubstance treated epidermal tissues is compared to that of negative control tissues. The quotient of the values indicates the relative tissue viability.

The EpiDerm™ skin corrosion/irritation test showed the following results:

The test substance is not able to reduce MTT directly.

Corrosion test:

The mean viability of the test-substance treated tissues determined after an exposure period of 3 minutes was 77%, and it was 94% after an exposure period of 1 hour.

Irritation test:

The mean viability of the test-substance treated tissues determined after an exposure period of 1 hour with about 42 hours post-incubation was 101%.

Based on the observed results and applying the evaluation criteria it was concluded, that EMIM Triflat does not show a skin irritation potential in the EpiDerm™ skin corrosion/irritation test under the test conditions chosen.