Methyl 2,3-dibromopropionate

Skin irritation / corrosion

Administrative data

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 2019-02-06 to 2019-02-08

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

Study performed to current OECD guidelines with no significant deviations and run in OECD GLP certified lab.

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: Reconstructed Human Epidermis (RHE) Test Method)

Version / remarks:

2016

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Methyl 2,3-dibromopropionate

EC Number:

217-044-3

EC Name:

Methyl 2,3-dibromopropionate

Cas Number:

1729-67-5

Molecular formula:

C4H6Br2O2

IUPAC Name:

methyl 2,3-dibromopropanoate

Test material form:

liquid

Specific details on test material used for the study:

Purity: 98%
Batch No.: 800327680

In vitro test system

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Justification for test system used:

Recommended test system in international guidelines (OECD and EC).

Vehicle:

unchanged (no vehicle)

Details on test system:

RECONSTRUCTED HUMAN EPIDERMIS (RHE) TISSUE
- Model used: EpiDerm Skin Model
- Tissue batch number(s): 29944 Kit I and J

TEMPERATURE USED FOR TEST SYSTEM
- Temperature used during treatment / exposure: at room temperature
- Temperature of post-treatment incubation (if applicable): 37.2 – 37.5 °C (actual range)

REMOVAL OF TEST MATERIAL AND CONTROLS : washed with phosphate buffered saline to remove residual test item, rinsed tissues were kept in 24 well plates on 300 µL DMEM until 6 tissues (= one application time) were dosed and rinsed.

MTT DYE USED TO MEASURE TISSUE VIABILITY AFTER TREATMENT / EXPOSURE
- MTT concentration: 5 mg/mL diluted (1:5)
- Incubation time: 3 hours
- Spectrophotometer: TECAN Infinite® M200 Pro Plate Reader
- Wavelength: 570 nm
- Linear OD range of spectrophotometer: 0.8 - 2.8

FUNCTIONAL MODEL CONDITIONS WITH REFERENCE TO HISTORICAL DATA
- Viability: 20 - 100%

NUMBER OF REPLICATE TISSUES: 2 tissues for 3-minute exposure and two for a 1-hour exposure, 2 tissues for the negative and positive controls for both the 3-minute and 1-hour time point

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): 50 µL
- Concentration (if solution): 98% (undiluted)

NEGATIVE CONTROL
- Amount(s) applied (volume or weight): 50 µL Milli-Q water

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

Duration of treatment / exposure:

3-minute and 1-hour

Number of replicates:

2 tissues for 3-minute exposure and two for a 1-hour exposure, 2 tissues for the negative and positive controls for both the 3-minute and 1-hour time point

Results and discussion

In vitro

Results

Results 1

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

3-minute treatment

Value:

29

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: Mean Tissue Viability

Results 2

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

1-hour treatment

Value:

2.4

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: Mean Tissue Viability

Other effects / acceptance of results:

- OTHER EFFECTS:
- Colour interference with MTT: the test item did not interfere with the MTT endpoint

ACCEPTANCE OF RESULTS:
- Acceptance criteria met for negative control: The absolute mean OD570 (optical density at 570 nm) of the negative control tissues was within the acceptance limits of OECD 431 (lower acceptance limit ≥0.8 and upper acceptance limit ≤ 2.8)
- Acceptance criteria met for positive control: The mean relative tissue viability following the 1-hour exposure to the positive control was 13%.
- Acceptance criteria met for variability between replicate measurements: ≤14% for the negative control; 36% for the positive control; Since both
individual tissues were clearly positive it was concluded that the test system functioned properly.
For the test item, the Coefficient of Variation between tissue replicates at the 3-minute exposure was 79%. Since both individual tissues were in the same category and clearly positive, it was concluded that this did not influence the outcome of the test.

Applicant's summary and conclusion

Interpretation of results:

Category 1B (corrosive) based on GHS criteria

Conclusions:

In conclusion, the test substance was corrosive in the in vitro skin corrosion test under the experimental conditions described in this report.

Executive summary:

This study was to evaluate the test substance for its ability to induce skin corrosion on a human three dimensional epidermal model (EpiDerm (EPI-200)) according to OECD 431. 

The possible corrosive potential of the test substance was tested through topical application for 3 minutes and 1 hour. The test item was applied undiluted (50 μL) directly on top of the skin tissue.

Skin corrosion is expressed as the remaining cell viability after exposure to the test item. The relative mean tissue viability obtained after 3-minute and 1-hour treatments with the test item compared to the negative control tissues was 29% and 2.4%, respectively. Because the mean relative tissue viability for the test substance was below 15% after the 1-hour treatment it is considered to be corrosive.

In conclusion, the test substance was corrosive in the in vitro skin corrosion test under the experimental conditions described in this report.