Thyme, Thymus mastichina, ext.

Eye irritation

Administrative data

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

14 may to 3 october 2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Report date:

2018

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 492 (Reconstructed Human Cornea-like Epithelium (RhCE) Test Method for Identifying Chemicals Not Requiring Classification and Labelling for Eye Irritation or Serious Eye Damage)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Thyme, Thymus mastichina, ext.

EC Number:

284-294-8

EC Name:

Thyme, Thymus mastichina, ext.

Cas Number:

84837-14-9

Molecular formula:

Not relevant for UVCB

IUPAC Name:

Thyme, Thymus mastichina, ext.

Test material form:

liquid: volatile

Test system

Controls:

yes, concurrent positive control

yes, concurrent negative control

Amount / concentration applied:

50µL

Duration of treatment / exposure:

30 minutes

Duration of post- treatment incubation (in vitro):

Tissues treated with liquid test items and with control substances tested concurrently to liquid test items are incubated for 30 ± 2 minutes at standard culture conditions

Number of animals or in vitro replicates:

two tissue replicates

Details on study design:

The test item Marjoram oil was applied, as supplied, at the dose of 50 µL, to 2 living DPBS pretreated RhCE (EpiOcular TM tissue model) during 30 minutes at 37°C, 5% CO2, 95% humidity (standard culture conditions). The exposure period was followed by extensive rinsing with DPBS at room temperature, a 12 minutes post-exposure immersion period at room temperature and a 2 hours post-exposure incubation at standard culture conditions. The tissue viability was measured by performing an MTT assay.
The experimental protocol was established in accordance with O.E.C.D. Test Guideline No. 492 adopted 09 October 2017.

Results and discussion

In vitro

Results

Results 1

Irritation parameter:

other: mean percent tissue viability (%)

Run / experiment:

sample 7 test item

Value:

44.43

Positive controls validity:

valid

Results 2

Irritation parameter:

other: mean percent tissue viability (%)

Run / experiment:

sample 8 test item

Value:

49.29

Positive controls validity:

valid

Applicant's summary and conclusion

Interpretation of results:

study cannot be used for classification

Conclusions:

The mean percent tissue viability of the RhCE replicates treated with the test item Marjoram oil was 46.86% versus 1.32% in the positive control (Methyl acetate).
In accordance with the Regulation EC No.1272/2008, the test item Marjoram oil has to be identified as potentially requiring classification and labeling according to UN GHS Category 2 or Category 1.