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Toxicological information

Eye irritation

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Administrative data

Endpoint:
eye irritation: in vivo
Type of information:
experimental study
Adequacy of study:
key study
Study period:
July-August 1989
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: According to ECVAM ToxRTool reliability 2. GLP study performed according to OECD guideline 405 of february 1987. Deficiencies: The description of the study results is not transparent and without further information missleading.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1989
Report date:
1989

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 405 (Acute Eye Irritation / Corrosion)
Deviations:
no
GLP compliance:
yes (incl. QA statement)

Test material

Constituent 1
Chemical structure
Reference substance name:
L-menthol
EC Number:
218-690-9
EC Name:
L-menthol
Cas Number:
2216-51-5
Molecular formula:
C10H20O
IUPAC Name:
2-isopropyl-5-methylcyclohexanol
Constituent 2
Reference substance name:
Cyclohexanol, 5-methyl-2-(1-methylethyl)-, [1R-(1.α.,2.β.,5.α.)]-
IUPAC Name:
Cyclohexanol, 5-methyl-2-(1-methylethyl)-, [1R-(1.α.,2.β.,5.α.)]-
Constituent 3
Reference substance name:
HR 89/620001
IUPAC Name:
HR 89/620001
Details on test material:
- Substance type: White crystalline powder (tiny crystals)
- Physical state: solid
- 64.3 % solubilised in diethyl phthalate
Substance purity : 99.7%
Expiration date of the lot : not stated

Test animals / tissue source

Species:
rabbit
Strain:
other: Chbb:HM, C.H. Boehringer, Biberach:Himalaya
Details on test animals or tissues and environmental conditions:
TEST ANIMALS
- Strain: SPF albino female rabbits Chbb:HM, C.H. Boehringer, Biberach; Himalaya
- Source: Dr Karl Thomae GmbH, D-7950 Biberach an der Riss 1.
- Weight at study initiation: 2600 to 2800 g
- Housing: Single PPL cages 45x55 cm with perforated floor
- Diet (e.g. ad libitum): free access to food pellets "Altromin 2123" from Chr. Petersen Ltd, DK-4100 Ringsted
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 1 week
- Controls: internal control (right eye)

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21 ± 2°C
- Humidity (%): 55 ± 15%
- Air changes (per hr): 6 times an hour
- Photoperiod (hrs dark / hrs light): 12 hours / 12 hours

Test system

Controls:
not required
Amount / concentration applied:
TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.1 ml
- Concentration 1 28.6%(W7W) L-Menthol in Dieethyl Phthalate (DEP) (in studie stated as vehicle)
- Concentration 2 :50 g L-Menthol + 50 g 28.6% (w/w) L-Menthol in DEP = 64.3% (w/w) in DEP
Duration of treatment / exposure:
No removal after application. Once applied the test material remained in contact with the eye throughout the experiment.
Observation period (in vivo):
Observation at 1 hour, 24 hours, 48 hours and 72 hours and 7 days.
Number of animals or in vitro replicates:
4 rabbits tested (female) for each concentration
Details on study design:
The day before testing both eyes of the animals were examined with an ophthalmoscope to ensure there were no eye defects or irritation. The examination was performed before and after instillation of oculoguttae flouresceini (Pb.N.),
Both the left and right eyes were treated. The right eyes with the vehicle and the left eyes with the test article solution.
About 0.1 ml of the test article concentration 1 or test article concentration 2 was placed in the left or right eye, respectively, of each rabbit by gently pulling the lower lid away from the eyeball to form a cup into which the test substance was dropped. The lids were then gently held together for about one second. The eyes were examined and the grade of ocular reaction was recorded 1 hour later. 24 hours later an examination was performed before and after instillation of oculoguttae flouresceini. After the examination the eyes were rinsed with 20 ml of a 0.9% sodium chloride solution
The eyes were also examined 48 and 72 hours after the treatment, as well as on day 7.

SCORING SYSTEM: see table below

Results and discussion

In vivo

Resultsopen allclose all
Irritation parameter:
cornea opacity score
Remarks:
opacity
Basis:
mean
Time point:
other: over all time points
Score:
1
Max. score:
4
Reversibility:
fully reversible within: 7 days
Remarks on result:
other: low concentration score 0.8
Irritation parameter:
iris score
Remarks:
lesion
Basis:
mean
Time point:
other: over all time points
Score:
0
Max. score:
2
Remarks on result:
other: low concentration score 0
Irritation parameter:
conjunctivae score
Remarks:
redness
Basis:
mean
Time point:
other: over all time points
Score:
2
Max. score:
3
Reversibility:
fully reversible within: 7 days
Remarks on result:
other: low concentration score 1.2
Irritation parameter:
conjunctivae score
Remarks:
oedema
Basis:
mean
Time point:
other: over all time points
Score:
0.6
Max. score:
3
Reversibility:
fully reversible within: 7 days
Remarks on result:
other: low concentration score 0.3
Irritant / corrosive response data:
For further details see table below

Any other information on results incl. tables

Results for left eye 64% L-Menthol:

Rabbit

Conjunctiva Discharge

Conjunctiva Redness

Conjunctiva Chemosis

Iris

Cornea

Opacity area (with fluoresceine)

#1 at 1 h

3

2

1

0

1

1

#1 at 24 h

1

2

1

0

1

4 (4)

#1 at 48 h

0

2

0

0

1

3 (3)

#1 at 72 h

0

1

0

0

1

3 (3)

#1 at 7 d

0

0

0

0

0

0

 

 

 

 

 

 

 

#2 at 1 h

3

2

1

0

1

2

#2 at 24 h

1

3

1

0

1

4 (4)

#2 at 48 h

0

2

0

0

1

2 (2)

#2 at 72 h

0

1

0

0

1

1 (1)

#2 at 7 d

0

0

0

0

0

0

 

 

 

 

 

 

 

#3 at 1 h

3

2

0

0

1

1

#3 at 24 h

1

3

2

0

1

4 (4)

#3 at 48 h

0

3

1

0

1

4 (4)

#3 at 72 h

0

2

1

0

1

3 (3)

#3 at 7 d

0

0

0

0

0

0

 

 

 

 

 

 

 

#4 at 1 h

3

2

1

0

1

3

#4 at 24 h

1

2

1

0

1

4 (4)

#4 at 48 h

0

2

0

0

1

3 (3)

#4 at 72 h

0

1

0

0

1

1 (1)

#4 at 7 d

0

0

0

0

0

0

 

 

 

 

 

 

 

24, 48 and 72 h mean

0.3

2.0

0.6

0.0

1.0

 

 

Applicant's summary and conclusion

Interpretation of results:
irritating
Remarks:
Migrated information Eye irritant category 2 under CLP, but does not meet eye irritant criteria under DSD. Criteria used for interpretation of results: EU
Conclusions:
Menthols causes moderate to intense reactions of rabbit eye cornea and conjunctiva, which is complete reversible within 7 days.
Executive summary:

The primary eye irritant effect of menthols was investigated using L Menthol in concentration of 29% and 64% according to the method recommended in the OECD Guideline No.405,“Acute Eye Irritation/Corrosion”, Feb. 1987.

Under the experimental conditions described in the report, moderate to intense reactions of cornea and conjunctiva were seen in all rabbits according to the used menthol concentration.  

All effects seen were fully reversible within 7 days.

 

Menthols should be classified as eye irritant category 2 under CLP but does not require classification for eye irritation/corrosion under DSD.