[No public or meaningful name is available]

Skin irritation / corrosion

Administrative data

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

13 January 2021 to 15 January 2021

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

The study is conducted in accordance with the relevant OECD test guideline and GLP. All validity criteria were met.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2021

Report date:

2021

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

18 June 2019

Deviations:

not specified

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: Method B.40bis of Commission Regulation (EC) No. 440/2008, of 30 May 2008, laying down test methods pursuant to Regulation (EC) No 1907/2006, 18 December 2006, of the European Parliament and of the Council on the Registration, Evaluation, Authorisation an

Version / remarks:

30 May 2008

Deviations:

not specified

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

4-hydroxy-3-methylbenzenesulphonic acid

Cas Number:

7134-04-5

Molecular formula:

C7H8O4S

IUPAC Name:

4-hydroxy-3-methylbenzenesulphonic acid

Test material form:

solid

In vitro test system

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Cell source:

other: Cell source not specified, all cells used to produce EpiDerm(TM) were purchased or derived from tissue obtained from accredited institutions where consent from donors and/or next of kins was obtained

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. The target cells are epithelial, derived from human skin, and formed into a stratified, cornified epithelium. Test items are applied to the culture surface, at the air interface, so that undiluted and/or end use dilutions can be tested directly.

Vehicle:

unchanged (no vehicle)

Details on test system:

RECONSTRUCTED HUMAN EPIDERMIS (RHE) TISSUE
- Model used: Epiderm(TM) Reconstructed Human Epidermis Model hit
- Tissue batch number(s):00267
- Production date:Not stated
- Shipping date: Not stated
- Delivery date: 12 January 2021
- Date of initiation of testing: 13 January 2021

TEMPERATURE USED FOR TEST SYSTEM
- Temperature used during treatment / exposure: 37 degC
- Temperature of post-treatment incubation (if applicable): NA

REMOVAL OF TEST MATERIAL AND CONTROLS
-Volume and number of washing steps: The tissues were rinsed for approximately 40 seconds
- Observable damage in the tissue due to washing: No
- Modifications to validated SOP: NA

MTT DYE USED TO MEASURE TISSUE VIABILITY AFTER TREATMENT / EXPOSURE
- MTT concentration: 1.0 mg/mL
- Incubation time: 60 minutes
- Spectrophotometer: Labtech LT-4500 microplate reader and LT-com analysis software
- Wavelength: 570 nm
- Filter: 10 nm
- Filter bandwidth:
- Linear OD range of spectrophotometer: Not stated


NUMBER OF REPLICATE TISSUES: Duplicate tissues


PREDICTION MODEL
- 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
- Amount applied : 25 mg

NEGATIVE CONTROL
- Amount applied: 50 μL
- Concentration (if solution): NA

POSITIVE CONTROL
- Amount(s) applied (volume or weight): 50μL
- Concentration (if solution):8.0 N

Duration of treatment / exposure:

3 minutes and 60 minutes

Duration of post-treatment incubation (if applicable):

3 hours

Number of replicates:

Two replicates

Results and discussion

In vitro

Results

Results 1

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

Run 1: (duration of exposure 3 minutes)

Value:

95

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

no indication of irritation

Results 2

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

Run 2 ( duration of exposure 60 minutes)

Value:

8.1

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

positive indication of irritation

Other effects / acceptance of results:

- OTHER EFFECTS:
- Visible damage on test system: Not stated
- Direct-MTT reduction: The test item did not turn blue/purple, the test item did not reduce MTT
- Colour interference with MTT: The solution containing the test item did not become coloured. This was taken to indicate the test item did not have the potential to cause colour interference.


ACCEPTANCE OF RESULTS:
- Acceptance criteria met for negative control: Yes, the mean OD570 for the negative control treated tissues was 1.734 for the 3-Minute exposure period and 1.879 for the 60-Minute exposure period.
- Acceptance criteria met for positive control: Yes, the relative mean tissue viability for the positive control treated tissues was 2.6% relative to the negative control following the 60-Minute exposure period.
- Acceptance criteria met for variability between replicate measurements: Yes, In the range 20 to 100% viability the Coefficient of Variation between the two tissue replicates of each treatment group did not exceed 30%.
- Range of historical values if different from the ones specified in the test guideline: Not stated

Any other information on results incl. tables

Table 1: Mean OD₅₇₀ Values and viabilities for the Negative Control Item, Positive Control Item and Test Item. 

 

Tissue	Exposure period	Mean OD570 of individual tissues	Mean OD570 of duplicate tissues	Standard Deviation	Coefficient of Variation (%)	Relative Mean Viability (%)
Negative Control	3 minutes	1.841	1.734	0.152	8.8	100%*
		1.6226
	60 minutes	1.851	1.879	0.039	2.1
		1.906
Positive Control	3 minutes	0.069	0.056	0.018	NA	3.2
		0.043
	60 minutes	0.058	0.048	0.014	NA	2.6
		0.038
Test item	3 minutes	1.784	1.648	0.193	11.7	95.0
		1.511
	60 minutes	0.163	0.153	0.014	9.2	8.1
		0.143

OD = Optical density

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

NA = Not applicable

Applicant's summary and conclusion

Interpretation of results:

Category 1B (corrosive) based on GHS criteria

Remarks:

The test item was considered to be corrosive UN GHS H314 Combination of sub-categories 1B and 1C.

Conclusions:

Under the conditions of this study, the test item is corrosive to the skin and a Category 1 (combination of sub-categories 1B and 1C) according to CLP Regulation (EC) No 1272/2008.

Executive summary:

The study was performed to OECD TG 431 under GLP to assess the corrosive potential of the test material when applied to human reconstructed skin - EpiDerm^TM. Duplicate tissues were treated with the negative control, positive control and the test item for  exposure periods of 3 minutes and 60 minutes. Cytotoxicity was assessed by the reduction of MTT to formazan by viable cells in the test item related tissues relative to the negative control with the optical density measured at 570 nm.

 

Results indicate that the test item did not reduce MTT with the percentage viability for cells treated with the test item was 95.5% and 8.1% after 3 and 60 minutes respectively. Under the conditions of the study the test item was considered to be corrosive to the skin and a classified in Category 1 according to the CLP Regulation (EC) 1272/2008.