5H-1,2-oxathiole 2,2-dioxide

Skin irritation / corrosion

Administrative data

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

18/06/2019 - 06/09/2019

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2019

Report date:

2019

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

2019

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

5H-1,2λ⁶-oxathiole-2,2-dione

EC Number:

606-834-7

Cas Number:

21806-61-1

Molecular formula:

C3H4O3S

IUPAC Name:

5H-1,2λ⁶-oxathiole-2,2-dione

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Shijiazhuang Suntec-chem Co.,Ltd; 190403
- Expiration date of the lot/batch: Apr 10, 2020
- Purity: 99.92%

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Store in cool place. Keep container tightly closed in a dry and well-ventilated place. Containers which are opened must be carefully resealed.
- Stability under test conditions: During the study the test item sample was stored in in original containers in a dry place.

In vitro test system

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Vehicle:

unchanged (no vehicle)

Details on test system:

RECONSTRUCTED HUMAN EPIDERMIS (RHE) TISSUE
- Model used: reconstructed human epidermal model EpiDerm™ (EPI-200-SCT)
- Tissue batch number(s): No. 30804, kit C

TEMPERATURE USED FOR TEST SYSTEM
- Temperature used during treatment / exposure: tissues were topically exposed to the test chemicals for 3 (room temperature) and 60 minutes at culture conditions (37±1°C, 5±1 % CO2, humidified).
- Temperature of post-treatment incubation (if applicable): 37±1°C, 5±1 % CO2, humidified.

REMOVAL OF TEST MATERIAL AND CONTROLS
- Volume and number of washing steps: After exposition, tissues were thoroughly rinsed and blotted to remove the test item/controls.
- Observable damage in the tissue due to washing: None


MTT DYE USED TO MEASURE TISSUE VIABILITY AFTER TREATMENT / EXPOSURE
- MTT concentration: 1 mg per mL
- Incubation time: 3 hours
- Spectrophotometer: Libra S22
- Wavelength: 570 nm

CONTROL TISSUES USED IN CASE OF MTT DIRECT/COLOUR INTERFERENCE
1. Functional check for MTT interference was performed as follows: 25 mg of the test item was added to 1 mL MTT medium (red) and incubated in the incubator (37±1°C, 5±1 % CO2, humidified) for 1 hour. At the end of the exposure time, the presence and intensity of the staining (if any) were observed.
2. Functional check for colour interference was performed as follows: 25 mg of the test item was added to 0.3 mL of water for injection and incubated in the incubator (37±1°C, 5±1 % CO2, humidified) for about 1 hour. At the end of the exposure time, the presence and intensity of the staining (if any) were observed. Another 25 mg of the test item was added to 2.0 mL of isopropyl alcohol and incubated at room temperature without shaking for 2 hours and 15 minutes. At the end of the exposure time, the presence and intensity of the staining (if any) were observed.

NUMBER OF REPLICATE TISSUES: Three tissues were used per the test item (C1), three for the the positive (PC) and three for the negative (NC) controls

PREDICTION MODEL / DECISION CRITERIA (choose relevant statement)
- 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(s) applied (volume or weight with unit): 25 mg of the test item with 25 μL of PBS

NEGATIVE CONTROL
- Amount(s) applied (volume or weight): 50 μL H2O

POSITIVE CONTROL
- Amount(s) applied (volume or weight): 50 μL 8N KOH

Duration of treatment / exposure:

3 minutes / 60 minutes

Duration of post-treatment incubation (if applicable):

3 hours

Number of replicates:

3 per group

Results and discussion

In vitro

Results

Results 1

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

test item-3 minutes treatment

Value:

106.6

Vehicle controls validity:

not examined

Negative controls validity:

valid

Positive controls validity:

valid

Results 2

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

test item-60 minutes treatment

Value:

92.5

Vehicle controls validity:

not examined

Negative controls validity:

valid

Positive controls validity:

valid

Results 3

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

positive control-3 min

Value:

6.2

Negative controls validity:

valid

Results 4

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

positive control-60 min

Value:

6.8

Negative controls validity:

valid

Other effects / acceptance of results:

- OTHER EFFECTS:
- Direct-MTT reduction: The test item did not reduce MTT directly
- Colour interference with MTT: The colour of the test material did not interfere with the endpoint

ACCEPTANCE OF RESULTS:
- Acceptance criteria met for negative control: The assay meets the acceptance criterion - OD570 of the NC tissues was 1.776 (3 min) and 1.712 (60 min) which is ≥ 0.8 and ≤ 2.8.
- Acceptance criteria met for positive control: Viability of tissues treated with 8N KOH after 60 minutes treatment was 6.8% which is ＜15%.
- Coefficient of variation: CV was higher than 0.3 in one case (see Table 1) but this was an acceptable deviation.

Any other information on results incl. tables

Table 1:MTT test results

Time	Treatment		OD570			Mean	SD	CV	% NC
			Tissues
			1	2	3
3 min	NC	water	1.64	1.847	1.842	1.776	0.096	0.054	100.0
	C1	152/19	1.877	1.907	1.898	1.894	0.013	0.007	106.6
	PC	8N KOH	0.115	0.109	0.108	0.111	0.003	0.028	6.2
60 min	NC	water	1.737	1.715	1.685	1.712	0.021	0.012	100.0
	C1	152/19	1.537	1.61	1.606	1.584	0.034	0.021	92.5
	PC	8N KOH	0.079	0.169	0.103	0.117	0.038	0.325	6.8

152/19 = 1,3 Propene Sultone

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Remarks:

Not classifed according to CLP

Conclusions:

In the in vitro skin corrosion test using the reconstructed human epidermal model EpiDermTM, the test item 1,3-Propene Sultone was non-corrosive.

Executive summary:

In an in vitro skin corrosion in the human epidermal model EpiDerm (152-19-4AC), reconstructed human epidermis tissue was exposed to 25 mg of 1,3-Propenesultone (99.92%) for 3 and 60 minutes. H2O was used for the negative control and 8N KOH was used for the positive control. After removal of the test substance, the tissues were incubated with MTT for three hours and then extracted with isopropyl alcohol overnight at room temperature with shaking. The OD570 of isopropyl alcohol extracts was measured on a spectrophotometer. Relative cell viability was calculated for each tissue as % of the mean viability of the negative control tissues.

The controls confirmed the validity of the study. The mean absolute OD570 of the three negative control tissues was ≥ 0.8 and ≤ 2.8 [1.776 (3 min) and 1.712 (60 min)]. The mean relative tissue viability (% negative control) of the positive control was < 15% [6.8% (60 min)]. Coefficient of variation (CV) was higher than 0.3 in one case but this was an acceptable deviation. The colour of the test substance did not interfere with the endpoint. The test substance is not directly MTT reducing. The average viability of tissues treated by the test item, 1,3-Propenesultone were higher than the threshold values (50 % and 15% respectively): 106.6 % ≥ 50% after 3 minutes exposure and 92.5% ≥ 15% after 60 minutes exposure. The test item should be regarded as non-corrosive.