Heavy wax residue fraction, waste plastic derived, hydrothermal conversion

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From September 8th, 2021 to September 10th, 2021

Reliability:

1 (reliable without restriction)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2021

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 439 (In Vitro Skin Irritation: Reconstructed Human Epidermis Test Method)

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.46 (In Vitro Skin Irritation: Reconstructed Human Epidermis Model Test)

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Heavy wax residue fraction, waste plastic derived, hydrothermal conversion

Molecular formula:

Not applicable - UVCB

IUPAC Name:

Heavy wax residue fraction, waste plastic derived, hydrothermal conversion

Test material form:

other: solid - lumps

Details on test material:

- Stability: stable under storage conditions
- Storage: room temperature (20 ± 5 °C)
- Appearance: large, brown, solid lumps
- Purity: not applicable, UVCB
- Homogeneity: homogeneous
- EC no.: 950-445-8

In vitro test system

Test system:

human skin model

Source species:

human

Cell type:

other: human-derived epidermal keratinocytes which have been cultured to form a multi-layered, highly differentiated model of the human epidermis

Details on test system:

The test system is a commercially available EpiDermTM-Kit, procured by MatTek.
The EpiDermTM tissue consists of human-derived epidermal keratinocytes which have been cultured to form a multi-layered, highly differentiated model of the human epidermis. It consists of organized basal, spinous and granular layers, and a multi-layered stratum corneum containing intercellular lamellar lipid layers representing main lipid classes analogous to those found in vivo. The EpiDermTM tissues are cultured on spe-cially prepared cell culture inserts.

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

Negative control: 30 µl DPBS buffer
Positive control: 30 µl 5% SDS
Test item: 25,6 mg, 26,2 mg, 26,3 mg

Duration of treatment / exposure:

1 hour

Duration of post-treatment incubation (if applicable):

42 h and 20 min

Number of replicates:

3

Results and discussion

In vitro

Results

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

1

Value:

87.5

Negative controls validity:

valid

Positive controls validity:

valid

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The test item Heavy wax residue fraction, waste plastic derived, hydrothermal conversion is considered non- irritant to skin in the Reconstructed human Epidermis (RhE) Test Method. The GHS criteria are not met.

Executive summary:

Three tissues of the human skin model EpiDerm^TM were treated with the test item for 60 minutes.

The test item was applied directly to each tissue and spread to match the tissue size (0.63 cm²; as indicated by the supplier).

DPBS-buffer was used as negative control and 5% SDS solution was used as positive control.

After treatment with the negative control, the mean absorbance value was within the required acceptability criterion of 0.8 ≤ mean OD ≤ 2.8, OD was 1.791.

The positive control showed clear irritating effects. The mean value of relative tissue viability was reduced to 2.3% (required: ≤ 20%).

The variation within the tissue replicates of negative control, positive control and test item was acceptable (required: ≤ 18%).

After the treatment with the test item, the mean value of relative tissue viability was reduced to 87.5% after correction. This value is above the threshold for skin irritation potential (50%). Test items that induce values above the threshold of 50% are considered non- irritant to skin.

Therefore, the test item Heavy wax residue fraction, waste plastic derived, hydrothermal conversion is considered non- irritant to skin in the Reconstructed human Epidermis (RhE) Test Method.