p-phenylene diisocyanate

Skin irritation / corrosion

Administrative data

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

14.11.2017-20.12.2017

Reliability:

1 (reliable without restriction)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

p-phenylene diisocyanate

EC Number:

203-207-6

EC Name:

p-phenylene diisocyanate

Cas Number:

104-49-4

Molecular formula:

C8H4N2O2

IUPAC Name:

1,4-diisocyanatobenzene

Test material form:

solid: crystalline

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: 170329
- Expiration date of the lot/batch: 28.03.2018
- Purity test date: 06.04.2017

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: at room temperature away from moisture
- Stability under test conditions: stable
- Solubility and stability of the test substance in the solvent/vehicle: not expected
- Reactivity of the test substance with the solvent/vehicle of the cell culture medium: not expected

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing: Test item (not diluted) will be applied directly atop the EpiDerm tissue (25 mg+25μl H2O: solids). Before testing, to identify the possible interference with MTT endpoint, test article will be checked for its ability to reduce MTT directly and/or colour interference.

In vitro test system

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Details on test system:

SKIN DISC PREPARATION
- Procedure used: EpiDerm™ was delivered one day before the pre-incubation of tissues and was stored in original package at 20±5 °C. At day 1, each culture was removed with sterile forceps from the agarose gel, inspected and transferred to a pre-labeled 6-well plates containing 0.9 mL of assay medium per well. The EpiDermTM cultures were incubated at 37±1°C in a humidified atmosphere of 5±1% CO2 in air for 1 hour.
TEMPERATURE USED FOR TEST SYSTEM
- Temperature used during treatment / exposure: not indicated
- Temperature of post-treatment incubation (if applicable): 37±1°C
REMOVAL OF TEST MATERIAL AND CONTROLS
- Number of washing steps: 20
- Observable damage in the tissue due to washing: no
DYE BINDING METHOD
- Dye used in the dye-binding assay: MTT
- Spectrophotometer: 96-well plate
- Wavelength: 540 nm
- Filter: without a reference filter
- Filter bandwidth: -
NUMBER OF INDEPENDENT TESTING RUNS / EXPERIMENTS TO DERIVE FINAL PREDICTION:
PREDICTION MODEL / DECISION CRITERIA (choose relevant statement)
- The test substance is considered to be corrosive to skin if [complete, e.g. if the mean TER value is less than or equal to 5 kΩ and the skin disk is obviously damaged, or if the mean TER value is less than or equal to 5 kΩ, and the skin disc is showing no obvious damage, but the mean disc dye content is greater than or equal to the mean disc dye content of the 10M HCl positive control obtained concurrently.]
- The test substance is considered to be non-corrosive to skin if [complete, e.g. if the mean TER value obtained for the test substance is greater than 5 kΩ, or if the mean TER value is less than or equal to 5 kΩ, and the skin disc is showing no obvious damage, and the mean disc dye content is well below the mean disc dye content of the 10M HCl positive control obtained concurrently.]

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): 25 mg
- Concentration (if solution): 25uL H2O

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

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

Duration of treatment / exposure:

3- min and 1-hour respectively

Duration of post-treatment incubation (if applicable):

3 hours

Number of replicates:

4: 2 3-min and 2 1-hour

Results and discussion

In vitro

Results

Results 1

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

3 min

Value:

ca. 97.5

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

no indication of irritation

Results 2

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

1 hour

Value:

ca. 89.7

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

no indication of irritation

Other effects / acceptance of results:

- OTHER EFFECTS:
- Visible damage on test system: not observed
- Direct-MTT reduction: not observed
- Colour interference with MTT: not observed

DEMONSTRATION OF TECHNICAL PROFICIENCY:

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
- Range of historical values if different from the ones specified in the test guideline: no

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The test item PPDI was examined for in vitro skin corrosion in human skin model test EpiDermTM.
Validity of the test method was ascertained by positive control 8N KOH. Two tissue replicates were used for each treatment (exposure time 3- minute and 1- hour), including controls.
The magnitude of viability was quantified by using MTT test.
The tissue viability met the acceptance criterion (mean OD of negative control was 1.802 and 1.904, respectively). The viability of culture treated by positive control 8N KOH was 16.8% and 4.6%, respectively. The positive control met the acceptance criterion: mean tissue viability less than 15% after one hour exposure.
The viability of culture treated by PPDI was 97.5% and 89.7%, respectively.
Determined viability of culture treated by PPDI fulfilled criteria for non-corrosivity.
It has been concluded that PPDI is considered to be non-corrosive to skin.

Executive summary:

PPDI was examined for in vitro skin corrosion in human skin model test EpiDermTM (EPI-200-SCT).

Two tissue replicates were used for each treatment (exposure time 3-min and 1- hr, respectively), including controls. The magnitude of viability was quantified by using MTT test. Validity of the test method was ascertained by positive control 8N KOH.

The tissue viability met the acceptance criterion (mean OD of negative control was 1.802 and 1.904, respectively). The viability of culture treated by positive control 8N KOH was 16.8% and 4.6%, respectively. The positive control met the acceptance criterion: mean tissue viability less than 15% after one hour exposure.

The viability of culture treated by PPDI was 97.5% and 89.7%, respectively.

Based on the results of the study, the test item PPDI according to Acceptance Criteria and Prediction Model is considered to be non-corrosive (NC).