4,4'-isopropylidenediphenyl dicyanate

Skin irritation / corrosion

Administrative data

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

February - April 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2016

Report date:

2016

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

other: B.40.Bis: “In Vitro Skin Corrosion: Human Skin Model Test

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

4,4'-isopropylidenediphenyl dicyanate

EC Number:

214-590-4

EC Name:

4,4'-isopropylidenediphenyl dicyanate

Cas Number:

1156-51-0

Molecular formula:

C17H14N2O2

IUPAC Name:

4-{2-[4-(cyanooxy)phenyl]propan-2-yl}phenyl cyanate

Test material form:

other: flaked solidified melt

Details on test material:

- Physical state: see above
- Appearance: see above

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Test Substance Name: LZ 514
- Source: Lonza Ltd, Visp/Switzerland
- Lot/batch No. of test material: 5011
- Expiration date of the lot/batch: 2nd December 2017
- Manufacture date: 3rd December 2015

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage conditions: Controlled room temperature (15-25 ºC, below 70 RH%), protected from light and humidity.
- Stability under test conditions: stable
- Safety precautions: Routine safety precautions (lab coat, gloves, safety glasses, face mask) for unknown materials were applied to assure personnel health and safety.

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:

SKIN DISC PREPARATION
- Procedure used: Adult human-derived epidermal keratinocytes are seeded on a dermal substitute consisting of a collagen type I matrix coated with type IV collagen.
- Quality control for skin discs: Electrical resistance obtained with two of the isolated skin discs was [complete, e.g. 10 kΩ]: The quality of the final product is assessed by undertaking a MTT cell viability test and a cytotoxicity test with sodium dodecylsulphate (SDS); conducted by the supplier.

TEMPERATURE USED FOR TEST SYSTEM
- Temperature used during treatment / exposure: plates with the treated epidermis units were incubated for 4 hours at room temperature (23.6-26.5°C)

REMOVAL OF TEST MATERIAL AND CONTROLS
- Number of washing steps: rinsed thoroughly with approximately 25 mL PBS (Phosphate Buffered Saline)
- Observable damage in the tissue due to washing: no

DYE BINDING METHOD
- Dye used in the dye-binding assay: MTT
- Wavelength: 570 nm

Control samples:

yes, concurrent negative control

yes, concurrent positive control

yes, concurrent MTT non-specific colour control

Amount/concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 20 mg test item

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

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

Duration of treatment / exposure:

4 hours incubation

Duration of post-treatment incubation (if applicable):

3 hours with MTT solution

Number of replicates:

In this assay, two replicates per test item were used. Two negative controls and two positive controls were also run in the assay. As the test item was coloured, two additional test item-treated tissues were used for the non specific OD evaluation.

Results and discussion

In vitro

Results

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

two experiments

Value:

82.7

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Other effects / acceptance of results:

- OTHER EFFECTS:
- Visible damage on test system: no
- Direct-MTT reduction: no interaction between test item and MTT
- Colour interference with MTT: no

ACCEPTANCE OF RESULTS:
- Acceptance criteria met for negative control: yes
- Acceptance criteria met for positive control: yes
- Acceptance criteria met for variability between replicate measurements: yes

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Following exposure with the test item, the mean cell viability was 82.7% compared to the negative control. This is above the threshold of 35%, therefore the test item was considered as being non-corrosive.

Executive summary:

An in vitro skin corrosivity test was performed in a reconstructed human epidermis model, according to testing methods OECDE 431 and EC B.40 bis. The corrosivity of the test item was evaluated according to the OECD No. 431 guideline.

Following exposure with the test item, the mean cell viability was 82.7% compared to the negative control. This is above the threshold of 35%, therefore the test item was considered as being non-corrosive. The experiment met the validity criteria, therefore the study was considered to be valid. In conclusion, in this in vitro EPISKIN model test, the results indicate that the test item is non corrosive to the skin.