Fatty acids, C18-unsatd., dimers, oligomeric reaction products with triethylenetetramine

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation / corrosion

Remarks:

in vitro

Type of information:

migrated information: read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Study period:

27th June 2012 to 13th November 2012.

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP study conducted according to relevant testing guidelines, with no deviations.

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

reference to same study

Cross-reference 2

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2012

Report date:

2012

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 431 (In Vitro Skin Corrosion: Human Skin Model Test)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.40 (In Vitro Skin Corrosion: Transcutaneous Electrical Resistance Test (TER))

Deviations:

no

Principles of method if other than guideline:

Not applicable.

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Fatty acids, C18-unsatd., dimers, oligomeric reaction products with tall-oil fatty acids and triethylenetetramine

EC Number:

500-191-5

EC Name:

Fatty acids, C18-unsatd., dimers, oligomeric reaction products with tall-oil fatty acids and triethylenetetramine

Cas Number:

68082-29-1

IUPAC Name:

Fatty acids, C18-unsatd, dimers, polymers with tall-oil fatty acids and triethylenetetramine

Constituent 2

Reference substance name:

TOFA_DimerFA_TETA_PAA

IUPAC Name:

TOFA_DimerFA_TETA_PAA

Test material form:

other: liquid

Details on test material:

- Name of test material (as cited in study report): TOFA_DimerFA_TETA_PAA
- Physical state: Yellow liquid with a brown hue
- Analytical purity: 100%
- Lot/batch No.: BB001030V1
- Expiration date of the lot/batch: 30th May 2013.
- Storage condition of test material: When not in use the test article was stored in a sealed container, at 15 to 25°C, in the dark.

Test animals

Species:

other: Not applicable - in vitro study

Strain:

other: Not applicable - in vitro study

Details on test animals or test system and environmental conditions:

Not applicable - in vitro study

Test system

Type of coverage:

other: Not applicable

Preparation of test site:

other: Not applicable

Vehicle:

unchanged (no vehicle)

Controls:

other: Not applicable

Amount / concentration applied:

In order to assess the potential non-specific reduction of the test article, 40 μL of test article was added to 0.3 mL of 1.0 mg/mL MTT.
A volume of 40 μL of the undiluted test article was added into the MILLICELL insert on top of the Epi-200 tissues.
Further tissues were concurrently treated with 40 μL purified water (negative control) and with 40 μL 8N potassium hydroxide (positive control).

Duration of treatment / exposure:

3 minutes and 1 hour.

Observation period:

Not applicable.

Number of animals:

Not applicable.

Details on study design:

In order to assess the potential non-specific reduction of the test article, 40 μL of test article was added to 0.3 mL of 1.0 mg/mL MTT and the colour change was assessed after three hours.
An increase in optical density was noted over the control (untreated MTT solution) therefore additional controls were included to enable assessment of the potential impact of the non-specific reduction of MTT by residual test article following the wash-off procedure.
To evaluate whether residual test article was binding to the tissue, a functional check (using freeze-killed control tissue) was performed. Freeze-killed tissues were prepared by placing untreated EpiDerm constructs in the -20°C freezer overnight. The freeze-killed tissues were allowed to thaw once at room temperature and placed back in the freezer overnight.

The EpiDermTM skin model is a three-dimensional human skin model, comprising a reconstructed epidermis with a functional stratum corneum. On the day of receipt EpiDermTM tissues were placed in a refrigerator. The next day, at least one hour before starting the assay, the tissues were transferred to 6-well plates with the assay medium, which was replaced immediately before the test was started. The test was performed on a total of four tissues per test article, negative and positive control, out of which two were used for a 3 minute application and two tissues were used for a 1 hour application. A volume of 40 μL of the undiluted test article was added into the MILLICELL insert on top of the Epi-200 tissues.
Further tissues were concurrently treated with 40 μL purified water (negative control) and with 40 μL 8N potassium hydroxide (positive control). After the 3-minute or 1-hour contact periods, the tissues were washed with phosphate buffered saline (PBS) to remove residual material. The rinsed tissues were kept in 24-well plates (holding plates) until all tissues were dosed and rinsed.

Once all tissues had been rinsed, they were transferred to wells containing 300 μL of 1 mg/mL MTT-medium and were incubated for 3 hours (37°C). After incubation, the tissues were washed with PBS and any resultant colour was extracted with 2 mL isopropanol overnight. The optical density of each resultant extract was determined spectrophotometrically at 570 nm and cell viability was calculated for each tissue as a percentage of the mean of the negative control tissue. Skin corrosivity potential of the test article was classified according to the remaining cell viability obtained after test article treatment with either of the two treatment times. Also to evaluate whether residual test article was binding to the tissue, a functional check (using freeze-killed control tissue) was performed. Freeze-killed tissues were prepared by placing untreated EpiDerm constructs in the -20°C freezer overnight. The killed tissues were allowed to thaw once at room temperature and were placed back at -20°C overnight.

Results and discussion

In vitro

Results

Results 1

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

3 minute

Value:

61

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Results 2

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

1 hour

Value:

35

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Any other information on results incl. tables

Three minute exposure period

Test substance	OD540			Mean	Tissue Mean	Difference between initial and freeze-killed tissues	% variability	% survival
Negative	2.164	2.383	2.261	2.269	2.225		-4.0	100
Negative	2.218	2.196	2.130	2.181
Test article	1.803	1.828	1.748	1.793	1.775	1.353	-2.0	61
Test article	1.749	1.759	1.764	1.757
Test article#	0.434	0.461	0.458	0.451	0.422		12.7
Test article#	0.393	0.394	0.394	0.394
Positive	0.470	0.521	0.530	0.507	0.496		4.443	22
Positive	0.483	0.483	0.488	0.485

# Freeze-killed tissues

One hour exposure period

Test substance	OD540			Mean	Tissue Mean	Difference between initial and freeze-killed tissues	% variability	% survival
Negative	2.160	2.437	2.434	2.344	2.298		-4.1	100
Negative	2.332	2.120	2.301	2.251
Test article	1.601	1.558	1.520	1.560	1.476	0.806	-12.0	35
Test article	1.427	1.391	1.361	1.393
Test article#	0.599	0.618	0.627	0.615	0.670		-18.1
Test article#	0.729	0.708	0.741	0.726
Positive	0.220	0.207	0.217	0.214	0.264		-45.942	11
Positive	0.312	0.308	0.319	0.313

# Freeze-killed tissues

Applicant's summary and conclusion

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The test article, TOFA_DimerFA_TETA_PAA, was not corrosive to skin in the in vitro skin model EpiDermTM.

Executive summary:

The potential of TOFA_DimerFA_TETA_PAA to cause skin corrosion was evaluated in an in vitro EpiDerm^TM study, conducted in compliance with GLP and according to OECD Test Guideline 431 and EU Method B.40.

Duplicate EpiDerm^TM inserts were treated with the test article, distilled water (negative control) and 8N potassium hydroxide (positive control) for 3 minutes and 1 hour. At the end of the treatment period, the tissues were washed with phosphate buffered saline (PBS) and cell viability was assessed using the MTT assay. The skin corrosivity potential was assessed according to the remaining cell viability obtained after test material treatment with either of the two treatment times. Skin viability after a three minute or one hour exposure to the test article was 61% and 35%, respectively. Skin viability after a three minute or one hour exposure to the positive control article was 22% and 11%, respectively, demonstrating appropriate performance of the assay. The test article, TOFA_DimerFA_TETA_PAA, was not corrosive to skin in the in vitro skin model EpiDerm^TM.