Registration Dossier

Registration Dossier

Diss Factsheets

Administrative data

Endpoint:
eye irritation, other
Remarks:
classification based on calculation rules for mixtures of the CLP Regulation
Type of information:
calculation (if not (Q)SAR)
Adequacy of study:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
accepted calculation method
Justification for type of information:
Classification based on calculation rules for mixtures of the CLP Regulation
Constituants data come from an online compilation using secondary data sources.

Data source

Referenceopen allclose all

Reference Type:
review article or handbook
Title:
Unnamed
Year:
2000
Report date:
2000
Reference Type:
other: Harmonized classification
Title:
Unnamed
Year:
2008
Report date:
2008

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 405 (Acute Eye Irritation / Corrosion)
GLP compliance:
not specified

Test material

Constituent 1
Chemical structure
Reference substance name:
Thymol
EC Number:
201-944-8
EC Name:
Thymol
Cas Number:
89-83-8
Molecular formula:
C10H14O
IUPAC Name:
5-(2-propenyl)-1,3-benzodioxole

Test animals / tissue source

Species:
rabbit
Strain:
not specified
Details on test animals or tissues and environmental conditions:
3 adult female albino rabbits (3.1 to 3.7 kg)

Test system

Vehicle:
unchanged (no vehicle)
Amount / concentration applied:
100µl
Observation period (in vivo):
7, 14 and 21 days
Number of animals or in vitro replicates:
3
Details on study design:
"The eye irritancy of thymol (99.5% pure) was tested in 3 adult female albino rabbits (3.1 to 3.7 kg) in accordance with OECD guideline No. 405. Each animal had 100 µl (bulk weight approx. 60 mg) instilled into the conjunctival sac of one eye, which was rinsed out with physiological saline solution after 24 hours. The findings were scored in accordance with the Draize method 1hour after rinsing out the eyes and again after 24, 48 and 72 hours as well as 7, 14 and 21 days. The irritation scores were 2 to 2.3 for the conjunctivae,1.0 for the iris and 1.3 to 2.7 for the cornea. Up to day 21 of the observation period all of the animals had positive fluorescein test results, and as of day 14 of the observation period, two rabbits developed pannus while the third
showed swelling in the lower part of the eyeball. On the basis of these irreversible findings, thymol was evaluated as a strong irritant (Bayer, 1986 b)."

Results and discussion

In vivo

Resultsopen allclose all
Irritation parameter:
conjunctivae score
Basis:
animal #1
Time point:
24/48/72 h
Score:
>= 2 - <= 2.3
Max. score:
4
Reversibility:
not specified
Irritation parameter:
conjunctivae score
Basis:
animal #2
Time point:
24/48/72 h
Score:
>= 2 - <= 2.3
Max. score:
4
Reversibility:
not specified
Irritation parameter:
conjunctivae score
Basis:
animal #3
Time point:
24/48/72 h
Score:
>= 2 - <= 2.3
Max. score:
4
Reversibility:
not specified
Irritation parameter:
iris score
Basis:
animal #1
Time point:
24/48/72 h
Score:
>= 1
Max. score:
4
Reversibility:
not specified
Irritation parameter:
iris score
Basis:
animal #2
Time point:
24/48/72 h
Score:
>= 1
Max. score:
4
Reversibility:
not specified
Irritation parameter:
iris score
Basis:
animal #3
Time point:
24/48/72 h
Score:
>= 1
Max. score:
4
Reversibility:
not specified
Irritation parameter:
cornea opacity score
Basis:
animal #1
Time point:
24/48/72 h
Score:
>= 1.3 - <= 2.7
Max. score:
4
Reversibility:
not specified
Irritation parameter:
cornea opacity score
Basis:
animal #2
Time point:
24/48/72 h
Score:
>= 1.3 - <= 2.7
Max. score:
4
Reversibility:
not specified
Irritation parameter:
cornea opacity score
Basis:
animal #3
Time point:
24/48/72 h
Score:
>= 1.3 - <= 2.7
Max. score:
4
Reversibility:
not specified
Irritation parameter:
chemosis score
Basis:
animal #1
Time point:
24/48/72 h
Score:
<= 4
Max. score:
4
Reversibility:
not specified
Irritation parameter:
chemosis score
Basis:
animal #2
Time point:
24/48/72 h
Score:
<= 4
Max. score:
4
Reversibility:
not specified
Irritation parameter:
chemosis score
Basis:
animal #3
Time point:
24/48/72 h
Score:
<= 4
Max. score:
4
Reversibility:
not specified

Applicant's summary and conclusion

Interpretation of results:
Category 1 (irreversible effects on the eye) based on GHS criteria
Conclusions:
Up to day 21 of the observation perid all of the animals had positive fluorescein test results, and as of day 14 of the observation period, two rabbits developed pannus while the third showed swelling in the lower part of the eyeball. Thymol was evaluted as a strong irritant.
Moreover, thymol is listed is annex 6 of European Regulation 1272/2008 and the hazard class is Skin corr. 1B and is classified H314 so equally classified H318 by default.
The classification of thymol is category 1 according to CLP and GHS criteria.
No study was conducted on the thyme oil iself.
The test item is a natural complex substance (NCS). It is a mixture of several constituents, and thymol represents about 51% of this UVCB substance. Literature above provided data for this major compound (see above data).
Executive summary:

The NCS is composed of several identified constituents, so it can be considered as a mixture according to the definition of the CLP Regulation. The decision logic for classification of mixtures from the ECHA Guidance on the Application of the CLP Criteria (2015) was used to determine the eye irritation / corrosion potential of the registered substance.

The registered substance has not been tested itself in appropriate in vitro or in vivo tests.

But one of its constituents is classified as eye corrosive (thymol at 51%).

The single constituent is present above the CLP generic concentration limit of 3% that triggers classification of the mixture. Therefore, the registered substance is classified as a eye corrosive substance without further testing according to the Regulation (EC) No 1272/2008.

EU Privacy Disclaimer

This website uses cookies to ensure you get the best experience on our websites.