Tall oil, maleated

Skin irritation / corrosion

Administrative data

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

May 2017-August 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:

Tall oil, maleated

EC Number:

268-859-6

EC Name:

Tall oil, maleated

Cas Number:

68152-93-2

Molecular formula:

UVCB

IUPAC Name:

3,7-dimethyl-14,16-dioxo-19-(propan-2-yl)-15-oxapentacyclo[10.5.2.0²,¹¹.0³,⁸.0¹³,¹⁷]nonadeca-13(17),18-diene-7-carboxylic acid; 8-(7-hexyl-1,3-dioxo-1,3,3a,4,7,7a-hexahydro-2-benzofuran-4-yl)octanoic acid

Test material form:

liquid

Details on test material:

Lot No.: HD0258QH13

Specific details on test material used for the study:

Viscous brown liquid

In vitro test system

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Cell source:

other: Cells purchased or derived from tissues obtained by accredited institutions from donor

Source strain:

other: 00267

Justification for test system used:

Recommended test system in international guidelines (OECD and EC)

Vehicle:

unchanged (no vehicle)

Remarks:

The liquid test item was applied undiluted (50 μl) directly on top of the tissue.

Details on test system:

EpiDerm Skin Model consists of normal, human-derived epidermal keratinocytes which have been cultured to form a multilayered, 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 arranged in patterns analogous to those found in vivo. The EpiDerm tissues (surface 0.6 cm²) were cultured on polycarbonate membranes of 10 mm cell culture inserts.

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

50 µl undiluted test item was added into the 6-well plates on top of the skin tissues.
For the negative and positive controls, 2 tissues were treated with 50 μl Milli-Q water (negative control) and 2 tissues were treated with 50 μl 8N KOH (positive control) for both the 3-minute and 1-hour time point.

Duration of treatment / exposure:

3 min and 1 hour treatment

Number of replicates:

2 replicates for test item per each exposure time (3 minutes/1 hour)
2 replicates for the positive control per each exposure time (3 minutes/1 hour)
2 replicates for the negative control per each exposure time (3 minutes/1 hour)

Results and discussion

In vitro

Results

Results 1

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

3 Minute application (first test)

Value:

60

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: Since the individual values for the 3-minute exposure were above and below the 50% (71 and 49% respectively) and the Coefficient of Variation was above 30%, the test was inconclusive and a repeat experiment for the 3-minute exposure was performed.

Results 2

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

3 minute application (second test)

Value:

79

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

no indication of irritation

Results 3

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

1 hour application

Value:

90

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

no indication of irritation

Other effects / acceptance of results:

EnvaMul 600 was checked for color interference in aqueous conditions and possible direct MTT reduction by adding the test item to MTT medium. Because the solutions did not turn blue / purple nor a blue / purple precipitate was observed it was concluded that EnvaMul 600 did not interfere with the MTT endpoint.

Any other information on results incl. tables

Mean Tissue Viability in the in vitro Skin Corrosion Test with EnvaMul 600

First test

3-minute application viability (percentage of control)

Negative control 100

EnvaMul 600 60

Positive control 7.4

Second test

3-minute application viability (percentage of control)

Negative control 100

EnvaMul 600 79

Positive control 9.2

1-hour application viability (percentage of control)

Negative control 100

EnvaMul 600 90

Positive control 5.3

Coefficient of Variation between Tissue Replicates

First test- 3 minute

Negative control 5.1

EnvaMul 600 31

Positive control 26

Second test- 3 minute

Negative control 10

EnvaMul 600 30

Positive control 7.9

1 hour

Negative control 6.8

EnvaMul 600 1.9

Positive control 9.2

CV (%) = 100 - [(lowest OD570/highest OD570) x 100%]

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

EnvaMul 600 is not corrosive in the in vitro skin corrosion test under the experimental conditions described in this report.

Executive summary:

The objective of this study was to evaluate EnvaMul 600 for its ability to induce skin corrosion on a human three dimensional epidermal model (EpiDerm (EPI-200)).

The possible corrosive potential of EnvaMul 600 was tested through topical application for 3 minutes and 1 hour. The study procedures described in this report were based on the most recent OECD and EC guidelines.

Batch HD0379UD11 of EnvaMul 600 was a viscous brown liquid. EnvaMul 600 was applied undiluted (50 μl) directly on top of the skin tissue. The positive control had a mean relative tissue viability of 5.3% after the 1-hour exposure. The absolute mean OD570 (optical density at 570 nm) of the negative control tissues was within the acceptance limits of OECD 431 (lower acceptance limit ≥0.8 and upper acceptance limit ≤2.8) and the laboratory historical control data range. In the range of 20 - 100% viability the Coefficient of Variation between tissue replicates was <7% for the negative control and 31% for the test item. Skin corrosion is expressed as the remaining cell viability after exposure to the test item. The relative mean tissue viability obtained after 3-minute and 1-hour treatments with EnvaMul 600 compared to the negative control tissues was 60% and 90%, respectively. However, since the individual values for the 3-minute exposure were above and below the 50% (71 and 49% respectively) and the Coefficient of Variation was above 30%, this part of the test was inconclusive and a repeat experiment for the 3-minute exposure was performed.

In the second test, the positive control had a mean relative tissue viability of 9.2% after the 3-minute exposure. The absolute mean OD570 (optical density at 570 nm) of the negative control tissues was within the acceptance limits of OECD 431 (lower acceptance limit ≥0.8 and upper acceptance limit ≤2.8) and the laboratory historical control data range. In the range of 20 - 100% viability the Coefficient of Variation between tissue replicates was ≤ 30%. The relative mean tissue viability obtained after 3-minute treatment with EnvaMul 600 compared to the negative control tissues was 79%. Because the mean relative tissue viability for EnvaMul 600 was not below 50% after the 3-minute treatment in the second experiment and not below 15% after the 1-hour treatment in the first experiment, EnvaMul 600 is considered to be not corrosive. In conclusion, EnvaMul 600 is not corrosive in the in vitro skin corrosion test under the experimental conditions described in this report.