Potassium (1R,3R)-3-[(1Z)-2-chloro-3,3,3-trifluoroprop-1-en-1-yl]-2,2-dimethylcyclopropanecarboxylate and Potassium (1S,3S)-3-[(1Z)-2-chloro-3,3,3-trifluoroprop-1-en-1-yl]-2,2-dimethylcyclopropanecarboxylate

Skin irritation / corrosion

Administrative data

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Experimental start date: 16 November 2017; Experimental termination date: 17 November 2017

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 431 (In Vitro Skin Corrosion: Reconstructed Human Epidermis (RHE) Test Method)

Version / remarks:

2016

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Potassium (1R,3R)-3-[(1Z)-2-chloro-3,3,3-trifluoroprop-1-en-1-yl]-2,2-dimethylcyclopropanecarboxylate and Potassium (1S,3S)-3-[(1Z)-2-chloro-3,3,3-trifluoroprop-1-en-1-yl]-2,2-dimethylcyclopropanecarboxylate

Cas Number:

82597-69-1

Molecular formula:

C9 H10 Cl F3 O2 . K

IUPAC Name:

Potassium (1R,3R)-3-[(1Z)-2-chloro-3,3,3-trifluoroprop-1-en-1-yl]-2,2-dimethylcyclopropanecarboxylate and Potassium (1S,3S)-3-[(1Z)-2-chloro-3,3,3-trifluoroprop-1-en-1-yl]-2,2-dimethylcyclopropanecarboxylate

Test material form:

solid

Specific details on test material used for the study:

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Room temperature in the dark

In vitro test system

Test system:

human skin model

Remarks:

https://www.mattek.com/products/epiderm/

Source species:

human

Cell type:

non-transformed keratinocytes

Cell source:

other: epithelial, derived from human skin

Source strain:

not specified

Justification for test system used:

This model incorporates several features, which make it advantageous in the study of potential dermal corrosivity

Details on test system:

Duplicate tissues were treated with the test item for exposure periods of 3 and 60 minutes. Negative and positive control groups were treated for each exposure period. At the end of the exposure period the test item was rinsed from each tissue before each tissue was taken for MTT loading. After MTT loading each tissue was placed in 2 mL isopropanol for MTT extraction.

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

25 mg of the test item

Duration of treatment / exposure:

3 and 60 minutes.

Number of replicates:

Duplicate tissues

Results and discussion

In vitro

Results

Results 1

Irritation / corrosion parameter:

% tissue viability

Remarks:

3 Minute exposure

Run / experiment:

Quantitative MTT assessment

Value:

49.6

Vehicle controls validity:

not specified

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

positive indication of irritation

Remarks:

See Table 1

Results 2

Irritation / corrosion parameter:

% tissue viability

Remarks:

60 Minute exposure

Run / experiment:

Quantitative MTT assessment

Value:

6.4

Vehicle controls validity:

not specified

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

positive indication of irritation

Remarks:

See Table 1

Any other information on results incl. tables

- Potential direct reduction of MTT by the test item was controlled. Experiment showed that MTT is not directly reduced by the test substance.

- The test item was colourless in solution in water. Therefore, it was considered that the test item does not cause colour interference in the test.

TABLE 1            Mean OD₅₇₀Values and Viabilities for the Negative Control Item, Positive Control Item and Test Item

Tissue	Exposure Period (minute)	Mean OD570of individual tissues	Mean OD570of duplicate tissues	Standard Deviation	Coefficient of Variation (%)	Relative Mean Viability (%)
Negative Control	3	1.683	1.805	0.173	9.6	100*
		1.927
	60	1.860	1.715	0.205	12.0
		1.570
Positive Control	3	0.087	0.076	0.016	na	4.2
		0.065
	60	0.056	0.056	0.000	na	3.3
		0.056
Test Item	3	0.936	0.896	0.057	6.3	49.6
		0.856
	60	0.107	0.110	0.004	na	6.4
		0.113

  *        The mean % viability of the negative control tissue is set at 100%

Applicant's summary and conclusion

Interpretation of results:

Category 1B (corrosive) based on GHS criteria

Remarks:

 This meets the criteria for classification as UN GHS H314 Combination of sub categories 1B and 1C.

Conclusions:

The mean percent cell viability for the Test Item at 3 and 60 minutes was 49.6% and 6.4%, respectively, therefore under the conditions of this assay the test item was considered to be corrosive to the skin. This meets the criteria for classification as UN GHS H314 Combination of sub categories 1B and 1C.

Executive summary:

The purpose of this test is to evaluate the skin corrosivity potential of the test item using the EpiDerm™ Human Skin Model after treatment periods of 3 and 60 minutes.

Corrosion is directly related to cytotoxicity in the EpiDerm™ tissue. Cytotoxicity is determined by the reduction of MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide) to formazan by viable cells in the test item treated tissues relative to the corresponding negative control. The results are used to make a prediction of the corrosivity potential of the test item.

Duplicate tissues were treated with the test item for exposure periods of 3 and 60 minutes. Negative and positive control groups were treated for each exposure period. At the end of the exposure period the test item was rinsed from each tissue before each tissue was taken for MTT‑loading. After MTT loading each tissue was placed in 2 mL isopropanol for MTT extraction.

At the end of the formazan extraction period each well was mixed thoroughly and three aliquots of 200 mL were transferred to the appropriate wells of a pre-labelled 96‑well plate. The optical density (OD) was measured at 570 nm (OD₅₇₀).

Data are presented in the form of percentage cell viability (MTT reduction in the test item treated tissues relative to negative control tissues).

The quality criteria required for acceptance of results in the test were satisfied.

 

The mean percent cell viability for the Test Item at 3 and 60 minutes was 49.6% and 6.4%, respectively, therefore under the conditions of this assay the test item was considered to be corrosive to the skin. This meets the criteria for classification as UN GHS H314 Combination of sub categories 1B and 1C.