Sodium 2-bromoethanesulphonate

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

10 May 2017 - 17 August 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

2015

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.46 (In Vitro Skin Irritation: Reconstructed Human Epidermis Model Test)

Version / remarks:

2012

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

other: SkinEthic Skin Irritation Test42bis Standard Operating Procedure

Version / remarks:

2009

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Sodium 2-bromoethanesulphonate

EC Number:

224-244-4

EC Name:

Sodium 2-bromoethanesulphonate

Cas Number:

4263-52-9

Molecular formula:

C2H5BrO3S.Na

IUPAC Name:

sodium 2-bromoethanesulphonate

Test material form:

solid

In vitro test system

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Justification for test system used:

The reconstructed human epidermis model in vitro method is an accepted in vitro method to replace animal testing. The human skin RHE™ model closely mimics the biochemical and physiological properties of the upper parts of the human skin, i.e the epidermis, and has been validated by the ECVAM in 2008.

Vehicle:

unchanged (no vehicle)

Details on test system:

RECONSTRUCTED HUMAN EPIDERMIS (RHE) TISSUE
- Model used: SkinEthic™ RHE-model RHE/S/17 (Episkin/SkinEthic Laboratories, Lyon, France)
- Tissue batch number: 17-RHE-071
- Date of initiation of testing: On day of receipt the pre-incubation phase of the tissues started

TEMPERATURE USED FOR TEST SYSTEM
- Temperature used during treatment / exposure: room temperature
- Temperature of post-treatment incubation: 37 °C

REMOVAL OF TEST MATERIAL AND CONTROLS
-Volume and number of washing steps: the test item, negative and positive control were removed immediately by gently rinsing with a minimum volume of 25 mL DPBS using a pipette. Excess DPBS was removed by gently shaking the tissue inserts and blotting the bottom of the tissue inserts with blotting paper.
- Observable damage in the tissue due to washing: No

MTT DYE USED TO MEASURE TISSUE VIABILITY AFTER TREATMENT / EXPOSURE
- MTT concentration: 1 mg/mL
- Incubation time: 3 h
- Spectrophotometer: ELx800 (BioTek Instruments GmbH, Bad Friedrichshall, Germany)
- Wavelength: 570 nm

NUMBER OF REPLICATE TISSUES: 3

NUMBER OF INDEPENDENT TEST SEQUENCES / EXPERIMENTS TO DERIVE FINAL PREDICTION: 1

PREDICTION MODEL / DECISION CRITERIA
- The test item is considered to be non-corrosive to skin if the tissue viability after exposure and post-treatment incubation is > 50%.
- The test item is considered to be irritant to the skin Category 2 if the viability is less than or equal to 50%

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

TEST MATERIAL
- Amount applied: 16 ± 2 mg

NEGATIVE CONTROL
- Amount applied: 16 ± 0.5 µL

POSITIVE CONTROL
- Amount applied: 16 ± 0.5 µL

Duration of treatment / exposure:

42 ± 1 min

Duration of post-treatment incubation (if applicable):

42 ± 1 h

Number of replicates:

3

Results and discussion

In vitro

Results

Results 1

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

1, Tissue 1

Value:

101.1

Vehicle controls validity:

not examined

Negative controls validity:

valid

Positive controls validity:

valid

Results 2

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

1, Tissue 2

Value:

101.3

Vehicle controls validity:

not examined

Negative controls validity:

valid

Positive controls validity:

valid

Results 3

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

1, Tissue 3

Value:

105.3

Vehicle controls validity:

not examined

Negative controls validity:

valid

Positive controls validity:

valid

Results 4

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

1, Mean

Value:

102.6

Vehicle controls validity:

not examined

Negative controls validity:

valid

Positive controls validity:

valid

Other effects / acceptance of results:

- OTHER EFFECTS:
- Visible damage on test system: No
- Direct-MTT reduction: No
- Colour interference with MTT: No


ACCEPTANCE OF RESULTS:
- Acceptance criteria met for negative control: Yes
- Acceptance criteria met for positive control: Yes
- Acceptance criteria met for variability between replicate measurements: Yes

Any other information on results incl. tables

Group	Tissue 1		Tissue 2		Tissue 3		Mean		SD
	OD	Viability (%)	OD	Viability (%)	OD	Viability (%)	OD	Viability (%)	Viability (%)
Negative Control	1.874	103.2	1.707	94.0	1.866	102.8	1.816	100.0	5.2
Positive Control	0.024	1.3	0.025	1.4	0.025	1.4	0.025	1.4	7.1
Test Item	1.836	101.1	1.839	101.3	1.913	105.3	1.863	102.6	2.3

Table 1: Optical Density and Tissue Viability

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

In an in vitro skin irritation assay according to OECD Guideline 439 (RhE), the test substance did not show skin irritating properties.

Executive summary:

In an in vitro skin irritation assay according to OECD Guideline 439 (RhE), the skin irritating properties of the test item were determined. The test item was applied topically to a human reconstructed skin model followed by determination of the cell viability. Cell viability was determined by enzymatic conversion of vital dye MTT into a blue formazan salt and measurement of the formazan salt after extraction from tissues. The percent reduction of cell viability in comparison to untreated negative controls was used to predict the skin irritation potential.

Triplicates of the human skin RHE-model were treated with the test item, the negative or the positive control for 42 minutes (± 1 minute). 16 µL of either the negative control (DPBS-buffer) or the positive control (5 % aqueous solution of sodium dodecyl sulfate) were applied to the tissues. Before application of 16 mg of the solid test item, 10 µL of deionised water was spread to the epidermis surface to improve the contact between the test item and the epidermis. All acceptability criteria after treatment with the negative control and the positive control were met.

Following treatment with the test item, the mean tissue viability was 102.6% and, thus, higher than 50%, i.e. according to OECD 439 the test item is considered as non-irritant to skin (UN GHS: No Category).