Phosphoric acid, decyl octyl ester

Skin irritation / corrosion

Administrative data

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From May 16, 2017 to June 15, 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

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:

Phosphoric acid, decyl octyl ester

EC Number:

269-041-1

EC Name:

Phosphoric acid, decyl octyl ester

Cas Number:

68186-45-8

Molecular formula:

C18H39O4P1 (representative: R = C8 and R1 = C10)

IUPAC Name:

Phosphoric acid, decyl octyl ester

Test material form:

liquid

Specific details on test material used for the study:

Supplier batch/lot No.: 0001146459; Appearance: colourless pale yellow liquid

In vitro test system

Test system:

human skin model

Remarks:

The reconstructed human epidermal model EpidermTM (EPI-200 MatTek Corporation)

Cell type:

other: normal human-derived epidermal keratinocytes

Justification for test system used:

The EpiDermTM skin model and assay for skin corrosion testing is endorsed by OECD TG 431.

Vehicle:

unchanged (no vehicle)

Details on test system:

Test system:

The reconstructed human epidermal model EpidermTM (EPI-200 MatTek Corporation) consists of normal human-derived epidermal keratinocytes which have been cultured to form a multi-layered highly differential model of the human epidermis. It consists of organised basal, spinous and granular layers and a multi-layered stratum corneum containing intercellular lamellar lipid layers arranged in patterns analogous to those found in vivo.

Characterisation of the test system:
MatTek’s EpiDermTM model has been extensively characterised for multiple parameters including morphology, tissue viability, skin barrier function and sterility. QC results for the specific lot of models received (Lot# 25819) were checked in-house for MatTek acceptance ranges with the following outcome:
- Morphology - PASS
- Tissue viability - PASS
- Skin barrier function (ET50 value for 1 % Triton X-100) where ET50 is the time taken for 1 % Triton X-100 to reduce the viability of the skin model to 50 % relative to the negative control) - PASS
- Sterility testing showed no contamination during long term antibiotic and antimycotic free culture - PASS

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

50 μl of neat test substance

Duration of treatment / exposure:

3 and 60 minutes at 37 °C, 5 % CO2, 95 % RH

Number of replicates:

3 replicates for test substance, negative and positive controls

Results and discussion

In vitro

Results

Results 1

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

3 minutes

Value:

16.5

Negative controls validity:

valid

Positive controls validity:

valid

Results 2

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

60 minutes

Value:

4.4

Negative controls validity:

valid

Positive controls validity:

valid

Other effects / acceptance of results:

- Prior to the assay, the test substance was checked for interference (water coloration or MTT interference) and found not to interfere.
- The test substance did reduce the viability below 50 % after 3 min and below 15 % after 1 h and should be considered as corrosive.

All acceptance criteria were met:
- The mean OD570 of the negative control tissues must be ≥0.8.
Result: 1.651 after 3 min, 1.869 after 1 h
- The mean of the positive control relative percentage viability, after 1 hour exposure must be <15 % of the mean of the negative control.
Result: 3.0 %
- In the range between 20 % and 100 % viability, the coefficient of variation (CV) is an additional acceptance criterion. It should not exceed 0.3 (i.e 30 %).
Results:
NC: 5.6 % after 3 min, 5.6 % after 1 h
PC: 22.8 % after 3 min, 15.0 % after 1 h
Test substance: 13.2 % after 3 min, 7.6 % after 1 h

Applicant's summary and conclusion

Interpretation of results:

other: Category 1A (corrosive) based on CLP criteria

Conclusions:

Under the study conditions, the test substance was determined to be skin corrosive, sub category 1A.

Executive summary:

An in vitro study was conducted to determine the skin corrosion potential of the test substance, mono- and di- C8-10 PSE, using the Reconstructed Human Epidermis (RHE) Test Method, according to OECD Guideline 431, in compliance with GLP. Three tissues of the human skin model EpiDermTM were used per treatment with the test substance, positive and negative control. 50 µL of the neat test substance was topically applied on each tissue model. Demineralised water was used as negative control, and KOH as positive control. After 3 minutes and 1 h treatment, the test substance or the control substance was rinsed off from the tissues. Then, cell viability of the tissues was evaluated by addition of MTT. Results were compared to negative control. All validity criteria for the performed test were met. After 3 minutes and 1 h treatment, the mean viability values obtained with the test substance were determined to be 16.5% and 4.4%. The test substance did reduce the viability below 50% after 3 min and below 15% after 1 hour and should be considered as corrosive. Under the study conditions, the test substance was determined to be skin corrosive (XcellR8, 2017).