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Toxicological information

Skin irritation / corrosion

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Administrative data

Endpoint:
skin irritation: in vivo
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2007
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
data from handbook or collection of data

Data source

Reference
Reference Type:
publication
Title:
Examination of a -terpinene on Primary Eye Irritancy and Skin Sensitization
Author:
Park B.S.
Year:
2007
Bibliographic source:
Mol. Cell. Toxicol. Vol. 3(1), 68-75, 2007
Report date:
2007

Materials and methods

Test guidelineopen allclose all
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 404 (Acute Dermal Irritation / Corrosion)
Qualifier:
according to guideline
Guideline:
other: Korean Food and Drug Administration (KFDA) guidelines
GLP compliance:
not specified

Test material

Constituent 1
Chemical structure
Reference substance name:
p-mentha-1,3-diene
EC Number:
202-795-1
EC Name:
p-mentha-1,3-diene
Cas Number:
99-86-5
Molecular formula:
C10H16
IUPAC Name:
1-isopropyl-4-methylcyclohexa-1,3-diene
Test material form:
liquid
Details on test material:
Clear colourless liquid.
Specific details on test material used for the study:
SOURCE OF TEST MATERIAL

- Source and lot/batch No.of test material: alpha terpinene was purchased from Sigma (St. Louis, MO)

FORM AS APPLIED IN THE TEST: Formulation of test repellents.
Repellent solution prepared using 0.5 g (2.0%) of alpha terpinene.

Test animals

Species:
rabbit
Strain:
New Zealand White
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: New Zealand white, Sejin Laboratory Co. (Seoul, South Korea)
- Age at study initiation: 12-18 weeks of age
- Weight at study initiation: male (2.8-3.3 kg) and female (2.7-3.4 kg)
- Acclimation period: yes, for 5 days before testing

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 16-21.6 °C
- Humidity (%): of 40-70%
- Air changes (per hr): not specified
- Photoperiod (hrs dark / hrs light): 12 h photoperiod


Test system

Type of coverage:
occlusive
Preparation of test site:
shaved
Remarks:
dorsal trunk
Vehicle:
other: Formulation of test repellents
Controls:
not specified
Amount / concentration applied:
TEST MATERIAL
- Amount(s) applied (volume or weight with unit): A volume of 0.5 mL repellent solution
- Concentration: 0.5 g (2.0%) of alpha terpinene in repellent solution

NEGATIVE CONTRL - yes

POSITIVE CONTROL - no
Duration of treatment / exposure:
4 hrours
Observation period:
24 h and 72 h
Number of animals:
Three males and three females were tested
Details on study design:
TEST SITE
- Area of exposure: dorsal trunk
- % coverage: 100% After applying the test compound polyethylene wrap was secured around the trunk of the rabbit. Rabbits were placed in a restraining cage for 4 h treatment. After that time which wraps were removed.
- Type of wrap if used: 1-inch square gauze patch was placed on the skin and secured with adhesive tape.

OBSERVATION TIME POINTS - 24 h and 72 h

SCORING SYSTEM: provided

Four different skin sensitivity cohorts were examined, as follows:
(1) non-treated at intact site (NTN group)
(2) non-treated at abraded site (NTA group),
(3) 2% a -terpinene solution at intact site (2TN group),
(4) 2% a -terpinene solution at abraded site (2TA group).

Each test rabbit had 3 intact sites and 3 abraded sites.

Results and discussion

In vivo

Resultsopen allclose all
Irritation parameter:
erythema score
Remarks:
scoring based on the final results
Basis:
mean
Time point:
24/48/72 h
Score:
> 0 - <= 2
Max. score:
4
Reversibility:
fully reversible
Remarks on result:
other: no scoring provided
Remarks:
No acute abnormalities were observed to intact or abraded skin after application of 2% alpha terpinene in rabbits.
Irritation parameter:
edema score
Remarks:
scoring based on the final results
Basis:
mean
Time point:
24/48/72 h
Score:
> 0 - <= 2
Max. score:
4
Reversibility:
fully reversible
Remarks on result:
other: no scoring provided
Remarks:
No acute abnormalities were observed to intact or abraded skin after application of 2% alpha terpinene in rabbits.

Applicant's summary and conclusion

Interpretation of results:
other: not skin irritant
Conclusions:
No acute abnormalities were observed to intact or abraded skin after application of 2% alpha terpinene in rabbits.




Executive summary:

In this study, the skin irritation potential was investigated in New Zealand white rabbits using the repellent solution containing 0.5 g (2.0%) of alpha terpinene.

The local skin reactions were read and recorded at 24 h and 72 h using the scoring system. A skin biopsy was taken at 72 h after treatment for histological studies. The skin biopsies were fixed in 10% buffered formalin solution for several days, then underwent ethanol series dehydration and embedded in paraffin. Sections were stained with hematoxylin-eosin and examined under a light microscope.

Results demonstrated, that no acute abnormalities were observed to intact or abraded skin after application of 2% alpha terpinene in rabbits.