Registration Dossier

Administrative data

Description of key information

Skin irritation: Irritating (Weight of evidence)
Serious eye damage/eye irritation: Not irritating

Key value for chemical safety assessment

Skin irritation / corrosion

Endpoint conclusion
Endpoint conclusion:
adverse effect observed (irritating)

Eye irritation

Link to relevant study records
Reference
Endpoint:
eye irritation, other
Remarks:
in vivo
Type of information:
experimental study
Adequacy of study:
key study
Study period:
25-05-1981 to 02-07-1981
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Study report which followed a known protocol (FDA/ Draize Method); acceptable restrictions.
Qualifier:
according to
Guideline:
other: FDA of the United States (fed, reg, 28 (119), 5582, 1963)/ Draize and Kelley (Drug Cosmet, Industr, 71(1952) 36)
Principles of method if other than guideline:
In general the techniques of tests as published by the FDA of the United States (Fed. Reg. 28 (119), 5582, 1963) and Draize and Kelley (Drug Cosmet. Induster. 71 (1952) 36) are followed.

Six New Zealand White albino rabbits are used for each test substance. The animals are caged individually and received no hay or other extraneous material that might enter the eyes.

The eyes of the animals are examined before testing and only those animals without observable eye defects and used. One tenth of a milliliter of the test substance, or in the case of solids or aemisolids, 100 milligrams of the test substance, is allowed to fall on the everted lower lid of one eye of each rabbit; the upper and lower eye lid are then carefully closed and subsequently held together for at least one second before releasing, to prevent loss of material. The other eye, remaining untreated, serves as a control.

The eyes are not washed following instillation and the animals are released immediately.

An animal is considered as giving a positive reaction if there is, at any of the readings, discernible opacity of the cornea (other than a slight dulling of the normal lustre), or ulceration of the cornea, or inflammation of the iris (other than a slight deeping of the folds (rugae) or a slight circumcorneal injection), or if such substance produces in the conjunctivae (palpebral and bulbar, excluding the cornea and iris) an obvious swelling with partial eversion of the lids, or a diffuse deep-crimson red with individual vessels not easily discernible. The FDA-scoring scale is used.

The test is considered positive if four or more of the animals in the test group of six rabbits exhibit a positive reaction. If one animal exhibits a positive reaction, the test is regarded as negative.

If two or three animals exhibit a postive reaction, the test is repeated, using a different group of six animals. The second test is considered as positive if three or more of the animals exhibit a positive reaction. If only one or two animals in the second test exhibit a positive reaction, the test is again repeated with a different group of six animals. Should be a third test be needed, the substance will be regarded as irritant if two or more animals exhibit a positive response.
GLP compliance:
not specified
Species:
rabbit
Strain:
other: New Zealand White albino rabbit
Vehicle:
unchanged (no vehicle)
Controls:
yes, concurrent no treatment
Amount / concentration applied:
TEST MATERIAL
- Amount(s) applied (volume or weight with unit): one tenth of a milliliter
Duration of treatment / exposure:
The treated eyes are not washed following instillation.
Observation period (in vivo):
24, 48, 72 hours and 7 days
Number of animals or in vitro replicates:
6 animals and unspecified sex
Details on study design:
REMOVAL OF TEST SUBSTANCE
- Washing (if done): No

SCORING SYSTEM: The method for grading ocular lesions is presented in Table 1 below.
Irritation parameter:
cornea opacity score
Basis:
animal: 1, 4 (individual mean)
Time point:
other: 24 h, 48h, 72h
Score:
0.67
Max. score:
1
Irritation parameter:
cornea opacity score
Basis:
animal: 2, 3, 5 (individual mean)
Time point:
other: 24h, 48 h, 72h
Score:
1
Max. score:
1
Irritation parameter:
cornea opacity score
Basis:
animal #6
Time point:
other: 24h, 48h, 72h
Score:
0
Max. score:
0
Irritation parameter:
iris score
Basis:
animal: 1, 2, 6 (individual mean)
Time point:
other: 24h, 48h, 72h
Score:
0.33
Max. score:
1
Irritation parameter:
iris score
Basis:
animal #3
Time point:
other: 24h, 48h, 72h
Score:
1
Max. score:
1
Irritation parameter:
iris score
Basis:
animal #4
Time point:
other: 24h, 48h, 72h
Score:
0
Max. score:
0
Irritation parameter:
iris score
Basis:
animal #5
Time point:
other: 24h, 48h, 72h
Score:
0.67
Max. score:
1
Irritation parameter:
conjunctivae score
Remarks:
redness
Basis:
animal: 1, 2, 6 (individual mean)
Time point:
other: 24h, 48h, 72h
Score:
1.67
Max. score:
2
Irritation parameter:
conjunctivae score
Remarks:
redness
Basis:
animal #3
Time point:
other: 24h, 48h, 72h
Score:
2.33
Max. score:
3
Irritation parameter:
conjunctivae score
Remarks:
redness
Basis:
animal: 4, 5 (individual mean)
Time point:
other: 24h, 48h, 72h
Score:
2
Max. score:
2
Irritation parameter:
chemosis score
Basis:
animal: 1, 5 (individual mean)
Time point:
other: 24h, 48h, 72h
Score:
1.67
Max. score:
2
Irritation parameter:
chemosis score
Basis:
animal #2
Time point:
other: 24h, 48h, 72h
Score:
2
Max. score:
3
Irritation parameter:
chemosis score
Basis:
animal #3
Time point:
other: 24h, 48h, 72h
Score:
2.33
Max. score:
3
Irritation parameter:
chemosis score
Basis:
animal #4
Time point:
other: 24h, 48h, 72h
Score:
1.67
Max. score:
3
Irritation parameter:
chemosis score
Basis:
animal #6
Time point:
other: 24h, 48h, 72h
Score:
1.33
Max. score:
2

Table 2: Individual scores awarded to the ocular lesions elicited by Ligustral

Rabbit number

Score

cornea iris Conjunctivae
 redness chemosis 
After 24 hours
1 1 1
2
3
4 0
After 48 hours
1
After 72 hours
1
2 1 0 1
After 7 days
1
5 0 0
0 0 0

 

Interpretation of results:
not classified
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
According to the FDA-standards, undiluted Ligustral is considered to be an eye irritant.
Executive summary:

In a primary eye irritation study (V81.203), 0.1 mL of undiluted Ligustral/Cyclal C/Trigustral was instilled into the eye lid of one eye of a New Zealand White albino rabbit (6 animals). The eye was not washed after instillation of the test article. Animals then were observed for 24 hr, 48 hr, 72 hr and 7 days after dosing. Irritation was scored using the system noted in Table 1.

The test substance caused slight corneal opacity in 5/6 rabbits, generally involving 50 -75% of the cornea, slight iritis also in 5/6 rabbits and moderate to severe redness and/or swelling of the conjunctivae in all animals. In addition five rabbits (no.1 through 5) showed moderate discharge of eye fluid. In the course of the seven-day observation period recovery of these lesions was observed but at the 7 -day reading one animal still showed slight corneal opacity, slight iritis and moderate conjunctivitis while two other animals showed slight redness of the conjunctivae.

In this study, Ligustral is an eye irritant based on the results of this test study according to FDA standards.

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion
Endpoint conclusion:
no study available

Additional information

Skin irritation/corrosion

A skin irritation study, a skin sensitization study and a dermal toxicity study were applied as weight of evidence. Based on the results of the studies, Ligustral/Cyclal C/Trigustral is a skin irritant.

In a skin irritation study (OECD 404, GLP), 4 rabbits were dermally exposed (semi-occlusive) to 0.5 mL of undiluted Ligustral/Cyclal C/Trigustral for 4 hrs. Animals were observed for 1hr, 24hr, 48hr, 72hr and 7 days after patch removal. The test substance caused well defined erythema in all treated animals (mean score: 2 – 2.2), slight oedema (mean score:1 - 2 ) in 3/4 rabbits and very slight oedema (mean score: 0 - 1) in 1/4 rabbit. The odema in 1 rabbit was fully reversible on Day 7 while 3/4 animals had very slight oedema remaining (max score:0.5) at Day 7. All animals had erythema still present by Day 7 (max score:2). Desquamation from the skin was observed in 2/4 animals at the 7 day time point.

In a skin sensitization study (OECD 406, GLP), Ligustral/Cyclal C/Trigustral (25% and 50% v/v in ethanol/diethylphthalate 1:1) was applied to flanks of female albino Dunkin Hartley guinea pigs (occlusive exposure) for 24hr (after intradermal induction and topical induction (14 days). The degree of erythema and odema was evaluated after 24 and 48 hrs. The test substance led to mild to moderate skin irritation (mean score: 1 - 2) in most animals. Some treated animals had adverse reactions that prevented accurate evaluation of erythema and oedema at the 48 hr observation period. The control animals did not have skin irritation during the observation period.

In a dermal toxicity study (1978), a 5000 mg/kg bw dose of Ligustral/Cyclal C/Trigustral was applied to the skin of 10 rabbits. On Day 1, two animals died. Irritation was assessed according to the following irritation parameters: skin redness, skin oedema, skin sloughing of exposure area and skin (hard/thickness). The number of rabbits showing skin irritation was: 1/8 moderate redness, 7/8 severe redness; 4/8 moderate oedema, 4/8 severe oedema. The following observations were noted during necropsy of all animals: skin sloughing of exposure area, 1/10; skin oedema, 7/8, skin redness, 9/10, and skin hard/thickness, 6/10. The LD 50 was > 5000 mg/kg bw.

Taking into account all of these studies as weight of evidence, Ligustral/Cyclal C/Trigustral is a skin irritant. The results from this study are acceptable to use in the human health risk assessment.

Serious eye damage/eye irritation

An in vivo eye irritation study was not required as an in vivo study was available. The in vivo eye irritant study was of acceptable quality and reliability with a Klimisch score of 2.

The following mean values, based on the results from the 24, 48 and 72 hour readings,were calculated:

cornea opacity: 3/6 animals 1; 2/6 animals 0.67; 1/6 animal 0

iris lesion: 1/6 animal 1; 1/6 animal 0.67; 3/6 animals 0.33; 1/6 animal 0.

conjunctival redness: 1/6 animal 2.33; 2/6 animals 2; 3/6 animals 1.67;

conjunctival oedema (chemosis): 1/6 animal 2.33; 1/6 animal 2; 3/6 animals 1.67; 1/6 animal 1.33.

In the study, Ligustral/Cyclal C/Trigustral is an eye irritant, according to FDA standards. As this study was conducted according to an older test method and six rabbits were used, the CLP regulation does not provide criteria for the evaluation of such studies. The current US EPA/UN Recommendations were considered as indicated in ‘Guidance on the application of the CLP criteria’, version 3.0, November 2012:

Classification as serious eye damage – Category 1 if at least in one animal effects on the cornea, iris or conjunctiva that are not expected to reverse or have not fully reversed within an observation period of normally 21 days; and/or at least 4 out of 6 rabbits show a mean score of:

≥ 3 for the cornea and/or

≥1.5 for the iris;

Classification as eye irritation – Category 2 if at least 4 out of 6 rabbits show a mean score of:

≥1 for the cornea and/or

≥1 for the iris and/or

≥2 conjunctival erythema and/or

≥2 conjunctival swelling.

Based on these criteria, Ligustral/Cyclal C/Trigustral is not an eye irritant. The results from this study are acceptable to use in the human health risk assessment.


Justification for selection of skin irritation / corrosion endpoint:
Three studies are presented as weight of evidence.

Justification for selection of eye irritation endpoint:
Only 1 key study available.

Effects on skin irritation/corrosion: irritating

Justification for classification or non-classification

Based on the available information in the dossier, the substance Ligustral/Cyclal C/Trigustral (CAS No. 68039-49-6) is classified as a skin irritant (Category 2) and does not need to be classified for serious eye damage/eye irritation when considering the criteria outlined in Annex I of 1272/2008/EC.