Phosphoric acid, decyl octyl ester

Endpoint summary

Description of key information

Based on the in vitro study results, the test substance, mono- and di- C8-10 PSE was determined to be corrosive to the skin and eyes.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Reference 1

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

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)

Specific details on test material used for the study:

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

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

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

3 minutes

Value:

16.5

Negative controls validity:

valid

Positive controls validity:

valid

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

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).

Reference 2

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From May 18, 2017 to May 23, 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

Deviations:

yes

Remarks:

see 'Principles of method if other than guideline'

Principles of method if other than guideline:

Optical Density (OD) values obtained with blanks were higher than 0.1 (0.1673) causing a deviation from acceptance criteria. This SOP and guideline deviation was not considered to have affected the integrity or interpretation of the results as no equivocal results were obtained.

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Supplier batch/lot No.: 0001146459; Purity: 100 %; Appearance: Colourless to pale yellow liquid

Test system:

human skin model

Remarks:

MatTek EpiDermTM tissue model EPI-200

Cell type:

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

Justification for test system used:

Initially the predictive capacity of the modified EpiDerm™ Skin Irritation Test (SIT) test method, using MatTek EpiDermTM tissue model EPI-200, underwent full prospective validation from 2003-2007. The test method components of this method were used to define the essential test methods components of the original and updated ECVAM Performance Standards (PS).
A modification of the original EpiDerm™ SIT was validated using the original ECVAM PS in 2008. In 2008, ESAC concluded that the Modified EpiDerm™ SIT has sufficient accuracy and reliability for prediction of R38 skin irritating and no-label (non-skin irritating) test substances.

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 differentiated 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# 25822) 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:

30 µL of the test substance

Duration of treatment / exposure:

60 ± 1 minutes of treatment

Duration of post-treatment incubation (if applicable):

42h ± 4 h

Number of replicates:

3 replicates for the test substance, positive and negative control

Irritation / corrosion parameter:

% tissue viability

Value:

4.9

Negative controls validity:

valid

Positive controls validity:

valid

Other effects / acceptance of results:

- Prior to the study, the required compatibility checks (as per SOP L0029) confirmed that the test substance did not interfere with MTT and no water colouration was observed.
- The test substance reduced the tissue viability to below 50 % and should be considered as Irritant to the skin.

All acceptance criteria were met with the exception of 1 criterion:

- The mean OD570 of the negative control (treated with DPBS) tissues is ≥0.8 and ≤2.8.
Result: 1.846
- The mean of the positive control relative percentage viability must be ≤20 % of the mean of the negative controls.
Result: 3.1 %
- The standard deviation of OD values for triplicate skin models in each experimental condition must be <18 %.
Results:
NC: 7.12 %
PC: 0.61 %
Test substance: 1.17 %
- The mean OD of the 6 wells containing extraction solvent alone (blanks) should be ≤0.1.
Result: 0.1673

Optical Density (OD) values obtained with blanks were higher than 0.1 (0.1673) causing a deviation from acceptance criteria. However, the spectrophotometer was fully validated and had passed all required tests. The OD values for blanks observed in this study are consistent with historical data using this spectrophotometer in the XCellR8 laboratory and meet our current internal acceptance criteria of blank OD values, therefore this is not considered to be an issue in the interpretation of this study data. This SOP and guideline deviation was not considered to have affected the integrity or interpretation of the results as no equivocal results were obtained.

Mean and SD of cell viability measurements and of viability percentages after a 60 minute application and 42h ± 2h post-incubation:

 

Name	Code	Mean of OD	SD of OD	Mean of viability (%)	SD of viability (%)	CV %	Classification
DPBS	NC	1.846	0.131	100.0	7.12	7.12	Non-Irritant
SDS 5%	PC	0.057	0.011	3.1	0.61	19.51	Irritant
Test substance	TS	0.090	0.022	4.9	1.17	23.94	Irritant

Interpretation of results:

other: Category 2 (irritant) based on CLP criteria

Conclusions:

Under the study conditions, the test substance, mono- and di- C8-10 PSE, was determined to be skin irritant.

Executive summary:

An in vitro study was conducted to determine the skin irritation potential of the test substance, mono- and di- C8-10 PSE (100%) using Reconstructed Human Epidermis Test Method, according to OECD 439 Guideline, in compliance with GLP. Three tissues of the human skin model EpiDermTM were treated with the test substance, positive or negative control for 60 minutes (25 minutes at room temperature and 35 minutes at 37 °C, 5 % CO2, 95 % RH) and 42 h post incubation period. Tissues were exposed to 30 µL of the neat test substance by topical application. 30 μL of DPBS was used as negative control and 5% of sodium dodecyl sulphate solution in water was used as positive control. Subsequently, viability of the tissues was assessed in MTT test and compared to the negative control. In the study, the percentage of viability obtained with the test substance was 4.9 %, therefore it was determined to be skin irritant. Under the study conditions, the test substance, mono- and di- C8-10 PSE was determined to be skin irritant (XCellR8, 2017).

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (corrosive)

Eye irritation

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irreversible damage)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Study 1: An in vitro study was conducted to determine the skin irritation potential of the test substance, mono- and di- C8-10 PSE (100%) usingReconstructed Human Epidermis Test Method,according to OECD 439 Guideline, in compliance with GLP. Three tissues of the human skin model EpiDermTM were treated with the test substance, positive or negative control for 60 minutes (25 minutes at room temperature and 35 minutes at 37 °C, 5 % CO2, 95 % RH) and 42 h post incubation period. Tissues were exposed to 30 µL of the neat test substance by topical application. 30 μL of DPBS was used as negative control and 5% of sodium dodecyl sulphate solution in water was used as positive control. Subsequently, viability of the tissues was assessed in MTT test and compared to the negative control. In the study, the percentage of viability obtained with the test substance was 4.9 %, therefore it was determined to be skin irritant. Under the study conditions, the test substance, mono- and di- C8-10 PSE was determined to be skin irritant (XCellR8, 2017).

Study 2: 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).

Justification for classification or non-classification

Skin irritation:

Based on the results ofin vitroskin irritation/corrosion studies, the test substance is determined to be skin corrosive with a classification as ‘Skin Corr. 1A; H314 - causes severe skin burns and eye damage’ according to EU CLP criteria (Regulation EC 1272/2008).

Eye irritation:

Based on the results ofin vivoskin irritation/corrosion studies, the test substance is determined to be corrosive to the eyes with a classification as ‘Eye Damage 1; H318- causes serious eye damage’ according to CLP criteria (Regulation EC 1272/2008). Labelling for this endpoint is covered by the above classifications for skin effects.