Vinyl 4-(1,1-dimethylethyl)benzoate

Skin irritation / corrosion

Administrative data

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

July - August 2021

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

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:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: Council Regulation 440/2008, Method B.40 BIS: “In Vitro Skin Corrosion: Human Skin Model Test”

Version / remarks:

May 30, 2008

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

other: MatTek Corporation Protocol for: In Vitro EpiDerm Skin Corrosion Test (EPI-200-SCT) For use with MatTek Corporation’s Reconstructed Human Epidermal Model EpiDerm

Version / remarks:

07/11/2014

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Vinyl 4-(1,1-dimethylethyl)benzoate

EC Number:

239-510-5

EC Name:

Vinyl 4-(1,1-dimethylethyl)benzoate

Cas Number:

15484-80-7

Molecular formula:

C13H16O2

IUPAC Name:

ethenyl 4-tert-butylbenzoate

Test material form:

liquid

Details on test material:

- Name: SAT 200028
- Batch No.: 19K2505
- Physical State: liquid
- Purity: 99.0%
- Expiry Date: 30 June 2021
- Storage Conditions: at room temperature, protected from light
- Safety Precautions: The routine hygienic procedures were sufficient to assure
personnel health and safety.

In vitro test system

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Cell source:

foreskin from a single donor

Justification for test system used:

The EpiDerm Skin Model is a well-established organotypic, three-dimensional model of the human
epidermis and is used for in vitro experiments since many years. It is known for its similarity to human skin.

Vehicle:

unchanged (no vehicle)

Details on test system:

The test was carried out with the reconstituted three-dimensional human skin model EpiDerm (MatTek). This skin model consists of normal (non-cancerous), human-derived epidermal keratinocytes (NHEK) which have been cultured to form a multi-layered, highly differentiated model of the human epidermis. The NHEK are cultured on chemically modified, collagen-coated cell culture inserts (Millicell). The EpiDerm skin model exhibits in vivo-like morphological and growth characteristics which are uniform and highly reproducible. It consists of organised basal, spinous, granular and cornified layers analogous to those found in vivo.

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

1. Negative control 50 μL distilled water
2. Positive control 50 μL 8 N KOH
3. Test Item 50 μL (undiluted)

Duration of treatment / exposure:

3 min / 60 min

Duration of post-treatment incubation (if applicable):

3 h MTT incubation

Number of replicates:

The test was performed on a total of 4 tissues per dose group, 2 replicates for each treatment period
(3 min and 60 min exposure time).

Results and discussion

In vitro

Results

Results 1

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

3 min exposure

Value:

97.9

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: no corrosive effects

Results 2

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

60 min exposure

Value:

94.2

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: no corrosive effects

Other effects / acceptance of results:

Test Acceptance Criteria
The controls confirmed the validity of the study. The mean OD570nm of the two negative control tissues was ≥ 0.8 and ≤ 2.8 for each exposure period (1.760, 1.747). The mean relative tissue viability (% negative control) of the positive control was ≤ 15% (6.1%) after 60 min treatment. The coefficient of variation (CV) (in the range of 20 – 100% viability) of replicate tissues of all dose groups was ≤ 30% (0.6% - 7.2).

Any other information on results incl. tables

Pre-Experiments
The mixture of 50 μL test item per 1 mL MTT medium showed no reduction of MTT as compared to the solvent. The mixture did not turn blue/purple. Therefore, NSMTT equalled 0%.
The mixture of 50 μL test item per 300 μL Aqua dest. and per 90 μL isopropanol showed no colouring as compared to the solvent. Therefore, NSC equalled 0%.
The test item showed no non-specific reduction of MTT and no relevant colouring potential after mixture with aqua dest. and with isopropanol. Therefore, no additional controls for correction of possible false-negative results were necessary.

Main Test
Corrosivity potential of the test item was predicted from the relative mean tissue viabilities obtained after both treatment periods had been compared to the corresponding negative control tissues.
The test item has no non-specific MTT-reducing or colouring potential, therefore no additional controls were necessary.
The test item showed no corrosive effects. The mean relative tissue viability (% negative control) was ≥ 50% (97.9%) after 3 min treatment and ≥ 15% (94.2%) after 60 min treatment.

Applicant's summary and conclusion

Interpretation of results:

other: non-corrosive

Conclusions:

In this study under the given conditions the test item showed no corrosive effects. The test item is
classified as “non-corrosive“.

Executive summary:

In the present study the skin corrosivity potential of SAT 200028 was analysed. Since corrosive chemicals are cytotoxic after a short time exposure to the stratum corneum of the epidermis the cytotoxic effects of the test item on EpiDerm, a reconstituted three-dimensional human epidermis model, were determined. Hereby, the test item was applied topically. Cytotoxicity is expressed as the reduction of mitochondrial dehydrogenase activity measured by formazan production from MTT after a 3 min and 60 min exposure period and compared to those of the concurrent negative controls.
The test item has no non-specific MTT-reducing or colouring potential, therefore no additional controls were necessary.
The test item showed no corrosive effects. The mean relative tissue viability (% negative control) was ≥ 50% (97.9%) after 3 min treatment and ≥ 15% (94.2%) after 60 min treatment.