Tar, wood

Eye irritation

Administrative data

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

27.02.2014

Reliability:

1 (reliable without restriction)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2014

Report date:

2014

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: Ocular Irritation Protocol: Neat Method (MTT ET-50) for use with EpiOcular TM Tissues, Rev: 17. Jan. 2012 by MatTek.

Deviations:

no

Principles of method if other than guideline:

SOP 118 00 890, edition 2 dated 01. Aug. 2013 ,“Bestimmung der hornhautreizenden Eigenschaften (Ermittlung ET50) mit EpiOcularTM“Additional: Stern M., Klausner M., Alvarado R., Renskers K., Dickens M., 1998. Evaluation of the EpiOcular Tissue Model as an Alternative to the Draize Eye Irritation Test. Toxicology in Vitro 12, 455-461

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Tar, wood

EC Number:

294-436-0

EC Name:

Tar, wood

Cas Number:

91722-33-7

Molecular formula:

not applicable

IUPAC Name:

Tar, wood

Test material form:

liquid: viscous

Details on test material:

Name Tar wood Batch no. 18092013 Appearance dark brown, viscous liquid Composition Mixture CAS No. 91722-33-7 EINECS-No. not stated Molecular formula not stated Molecular weight not stated Purity 100% mixture Homogeneity not stated Vapour pressure not stated Stability not stated Solubility not indicated by the sponsor Production date not stated Expiry date 31. Dec. 2015 Storage Room temperature 20 ± 5 °C

Test animals / tissue source

Species:

other: three-dimensional human cornea model tissue

Strain:

other: not applicable (this is an invitro test)

Test system

Vehicle:

other: not applicable (this is an invitro test)

Controls:

other: not applicable

Duration of treatment / exposure:

3 min., 30 min. and 60 min.

Number of animals or in vitro replicates:

not applicable

Results and discussion

In vitro

Results

Irritation parameter:

other: ET50

Run / experiment:

EpiOcular Test

Value:

32.63

Negative controls validity:

valid

Positive controls validity:

valid

Any other information on results incl. tables

The test item showed the ability of direct Formazan reduction. Therefore, a functional test with freeze-killed tissues was performed and all measured values were corrected by the net formazan reduction of the freeze-killed tissues.

After 3 minutes treatment with the test item, the corrected relative absorbance values were reduced to 63.2 %. After 30 minutes treatment, corrected relative absorbance values were reduced to 57.5%. And after 60 minutes treatment, the corrected relative absorbance values were reduced to 31.9%.

From these values, the ET₅₀was calculated mathematically. The calculated ET₅₀of the test item Tar wood was 38.82 min.

The test item is considered as mild eye irritant.

The criterion for optical density of the negative control was fulfilled: The optical density of 1.746 is in the range of the historical data.

The positive control induced a decrease in the relative absorbance as compared to the negative control to 75.3 % for the 45 minutes treatment interval and 32.2 % for the 15 minutes treatment interval. The calculated ET₅₀was 32.63 min., thus ensuring the validity of the test system.

Applicant's summary and conclusion

Interpretation of results:

other: mild irritant

Remarks:

Criteria used for interpretation of results: other: see table 7.5-a in the final report

Conclusions:

Tar wood is classified as mild eye irritant in the Human Cornea Model test.

Executive summary:

In the pre-test, the test item Tar wood showed the ability of direct formazan reduction. Therefore, a functional check with freeze killed tissues was performed as well.

In the main study, the test item Tar wood was applied to a three-dimensional human cornea model tissue for three different exposure times in duplicate (3 min., 30 min. and 60 min.).

100 µL of the liquid test item were applied to each tissue.

Demin. water was used as negative control, 0.3% Triton X 100 solution was used as positive control.

After treatment, the respective substance was rinsed from the tissue; then, cell viability of the tissues was evaluated by addition of MTT which can be reduced to a blue formazan. Formazan production was measured by measuring the optical density (OD) of the resulting solution.

After treatment with the negative control, the absorbance values were well within the historical range and showed no cytotoxic effects. The positive control showed clear irritating effects for both treatment intervals.

After 3 minutes treatment with the test item, the relative absorbance values were reduced to 63.2 %. After 30 minutes treatment, relative absorbance values were reduced to 57.7 %. And after 60 minutes treatment, the relative absorbance values were reduced to 31.9 %. These values were calculated after subtraction of direct formazan reduction.

From these values, the ET₅₀was calculated mathematically. The calculated ET₅₀of the test item Tar wood was 38.82 min.

Therefore, the test item Tar wood is classified as mild eye irritant in the Human Cornea Model test.