4,4'-[2,2,2-trifluoro-1-(trifluoromethyl)ethylidene]diphthalic anhydride

Skin irritation / corrosion

Administrative data

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

December 2021

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Deviations occurred but these did not have an effect on the study as all acceptance criteria were met.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2022

Report date:

2022

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Deviations:

yes

Remarks:

See 'any other information on materials and methods'

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

4,4'-[2,2,2-trifluoro-1-(trifluoromethyl)ethylidene]diphthalic anhydride

EC Number:

214-170-0

EC Name:

4,4'-[2,2,2-trifluoro-1-(trifluoromethyl)ethylidene]diphthalic anhydride

Cas Number:

1107-00-2

Molecular formula:

C19H6F6O6

IUPAC Name:

4,4'-(hexafluoroisopropylidene)diphthalic anhydride

Specific details on test material used for the study:

Batch number: CT20201015
Purity: 94.1815%
Retest date: 10th September 2022
Storage temperature: 15 - 25 oC

In vitro test system

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Cell source:

other: MatTek’s EpiDermTM model

Vehicle:

unchanged (no vehicle)

Details on test system:

RECONSTRUCTED HUMAN EPIDERMIS (RHE) TISSUE

- Model used: MatTek’s EpiDermTM model
- Tissue batch number(s): 36115
- Delivery date: 21st December 2021
- Date of initiation of testing: 20th December 2021

After removal from the refrigerator, the tissues were placed in 0.9 mL of assay medium and incubated under standard culture conditions (in a humidified incubator set to 37°C, 5% CO2) for 60±5 minutes. After removal from the incubator, tissues were pre-wetted with 25 µL sterile water, followed by application of test or reference item was applied to three tissues per condition for 3 or 60 minutes followed by rinsing with DPBS. Tissues from both timepoints were placed in 300µL of 1 mg/mL MTT solution and incubated at standard culture conditions for 3 hours±5 minutes. After removal from the incubator the MTT solution was removed and 1 mL MTT extractant added to each tissue insert and incubated overnight in the dark (without shaking). This was followed by 15 minutes of gentle shaking. After extraction, 2 x 200 µL aliquots from each tissue, and 6 x 200 µL aliquots of MTT extractant (blanks) were transferred to a reading plate and absorbance optical density was measured at 570 nm without reference filter. A FLUOstar Omega Spectrophotometer was used.



FUNCTIONAL MODEL CONDITIONS WITH REFERENCE TO HISTORICAL DATA
- Viability: PASS (1.880 h) The Optical density value should be between >0.8 and <2.8h
- Barrier function: PASS (5.33 h) ET50 should be between 4 and 8.7 hours
- Morphology: PASS (88.7 um) Tissue thickness should be between 70 and 130 um
- Contamination: PASS - no evidence of contamination


PREDICTION MODEL / DECISION CRITERIA

A test item is classified "corrosive", if the relative tissue viability after 3 minute treatment with a test material is decreased below 50%.

In addition, those materials classified "non-corrosive" after 3 minute treatment (viability ≥ 50%) are classified "corrosive" if the relative tissue viability after 1 hour treatment with a test material is decreased below 15%.

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

Single topical application of 50 µL of neat test item; 50 µL of reference items for 3 and 60 minutes to the surface of the EpiDermTM skin models, in humidified conditions at 37°C, 5% CO2, prior to the MTT endpoint; three tissues per condition (n=3).

Duration of treatment / exposure:

3 and 60 minutes

Duration of post-treatment incubation (if applicable):

3 hours +/- 5 minutes

Number of replicates:

three tissues per endpoint

Results and discussion

In vitro

Results

Results 1

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

Mean of three runs (duration of exposure: 1 hour)

Value:

95.929

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Results 2

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

Mean of three runs (duration of exposure: 3 minutes)

Value:

87.082

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Other effects / acceptance of results:

Acceptance criteria 1 - The mean OD570 of the negative control tissues must be ≥0.8. The actual values were 2.035 for the 3 minute experiment and 2.266 for the 1 hour experiment. PASS

Acceptance criteria 2 - The mean of the positive control relative percentage viability, after 1 hour exposure must be < 15% of the mean of the negative control. The actual value was 13.080%. PASS

Acceptance Criteria 3 - In the range between 20% and 100% viability, the coefficient of variation (CV) is an additional acceptance criterion. It should not exceed 0.3 (30%).

CV at 3 minutes - PASS
Negative control - 11.777%
Positive control - 23.489%
Test item - 3.771

CV at 1 hour - PASS
Negative control - 3.905%
Positive control - 43.823%*
Test item - 18.599%

*Note that the CV value of the PC after 1 hour was above 30% (43.823%). However, as the percentage of viability was below 20% (13.080%), acceptance criterion 3 is met.

Applicant's summary and conclusion

Interpretation of results:

study cannot be used for classification

Remarks:

No information can be gained regarding skin irritancy of test item using this test method.

Conclusions:

4,4’-[2,2,2-trifluoro-1-(trifluoromethyl)ethylidene]diphthalic anhydride was classified as Non-Corrosive to human skin.

Executive summary:

The skin corrosion potential of 4,4’-[2,2,2-trifluoro-1-(trifluoromethyl)ethylidene]diphthalic anhydride was assessed in vitro according to OECD Test Guideline 431 (In Vitro Skin Corrosion: Reconstructed Human Epidermis Test Method).

After a 3 minute and 1 hour exposure on the surface of EpiDerm^TM reconstructed human epidermis, the viability of the tissues was assessed and compared to a negative control.

The percentage viabilities obtained after 3 minutes and 1hr were 95.929% and 87.082% respectively and therefore 4,4’-[2,2,2-trifluoro-1-(trifluoromethyl)ethylidene]diphthalic anhydride was classified as Non-Corrosive to human skin.