Despite the various effects on the health of Chamaecyparis obtusa essential oil (COEO), an adverse effect on the skin has recently been reported. Therefore, in this study, the skin sensitization test of COEO was conducted to confirm the skin safety of the essential oil by the guinea pig maximization test. Guinea pigs were sensitized with intradermal injection of 0.1ml COEO for 24 h. After 1 week, 5% of COEO was treated on the site of injection and 2% of the essential oil was challenged 2 weeks later. The average skin reaction evaluated by erythema and edema on the challenge sites and sensitization rate in the COEO-treatment group at 24 h were 0.0 and 0%, respectively, which are substantially low compared with in the 2,4-dinitrochlorobenzene-treatment group (positive control group) (average skin reaction: 3.0, sensitization rate: 100%) and identical with in the olive oil-treatment group (negative control group), representing a weak sensitizing potential. The average skin reaction and sensitization rate observed at 48 h were 0.0 and 0% in the COEO-treatment group, respectively, and 2.0 and 100% in the positive control group, respectively. It was concluded that 5% of COEO classified to Grade I, induced no sensitization when tested in guinea pigs.

Abstract
서 론
재료 및 방법
    시험 물질
    실험동물
    피부 감작성 시험
    관찰 및 평가
결 과
    일반증상 및 체중변화
    감작항원량 및 야기항원량
    피부 감작성 평가
고 찰
REFERENCES

• Du Hyeon Hwang(Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University)
• Eun-Kee Park(Department of Medical Humanities and Social Medicine, College of Medicine, Kosin University)
• Chang-Yeul Yoo(Department of Smart Information Convergence, Gyeongnam Provincial Namhae College)
• Suk Kim(Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University)
• Euikyung Kim(Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University) Corresponding Authors.
• Hu-Jang Lee(Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University) Corresponding Authors.