title: Primary irritation index and safety zone of cosmetics: retrospective analysis of skin patch tests in 7440 Korean women during 12 years.
abstract: BACKGROUND
  Cosmetics are products used over long periods by the public, and their safety is very important. Several types of human tests are used widely for the evaluation of cosmetics including single patch tests, in-use tests, human repeated insult patch test (HRIPT). However, there is no clear and well-defined published objective and standardized criteria for primary skin irritation in regard to the large variety of cosmetic products.
  
  
  METHODS
  This study analysed human patch tests conducted from May 2001 to December 2012 with 4606 materials of prototype or finished cosmetic products on 7440 normal Korean women aged 18-60 years. The tested products were patched under occlusion for 24 or 48 h, and skin tolerance was assessed twice at 30 min and 24 h after patch removal using a 5-step scale according to the CTFA guidelines.
  
  
  RESULTS
  Human patch tests for cosmetics were performed of 4606 cases, and 30-33 subjects participated in each case. The response in each case was calculated based on total subject number, skin reaction intensity and the number of respondents. The calculated response was standardized using the z-score, and a safety zone was provided in terms of human primary irritation in accordance with the human skin reaction evaluation criteria and usage or formula of cosmetics.
  
  
  CONCLUSIONS
  This study established the safety criteria for irritation in the cosmetics field.
authors.affiliation: Dermapro Skin Research Center, DERMAPRO LTD, 4F Jiho B/D, Bangbaejoongang-Ro 30, Seocho-Gu, Seoul, South Korea.
authors.forename: S M
authors.initials: SM
authors.lastname: An
authors.affiliation: Dermapro Skin Research Center, DERMAPRO LTD, 4F Jiho B/D, Bangbaejoongang-Ro 30, Seocho-Gu, Seoul, South Korea.
authors.forename: H
authors.initials: H
authors.lastname: Ham
authors.affiliation: Dermapro Skin Research Center, DERMAPRO LTD, 4F Jiho B/D, Bangbaejoongang-Ro 30, Seocho-Gu, Seoul, South Korea.
authors.forename: E J
authors.initials: EJ
authors.lastname: Choi
authors.affiliation: Dermapro Skin Research Center, DERMAPRO LTD, 4F Jiho B/D, Bangbaejoongang-Ro 30, Seocho-Gu, Seoul, South Korea.|Department of Dermatology, College of Medicine, Kyung Hee University, Seoul, South Korea.
authors.forename: M K
authors.initials: MK
authors.lastname: Shin
authors.affiliation: Amorepacific R&D Center, 314-1, Bora-dong, Giheung-gu, Yongin-si, Gyeonggi-do, South Korea.
authors.forename: S S
authors.initials: SS
authors.lastname: An
authors.affiliation: Department of Dermatology, Seoul St. Mary's Hospital, College of Medicine, Catholic University Seoul, South Korea.
authors.forename: H O
authors.initials: HO
authors.lastname: Kim
authors.affiliation: Dermapro Skin Research Center, DERMAPRO LTD, 4F Jiho B/D, Bangbaejoongang-Ro 30, Seocho-Gu, Seoul, South Korea.
authors.forename: J S
authors.initials: JS
authors.lastname: Koh
mesh_terms: D000293:Adolescent; D000328:Adult; D003358:Cosmetics; D005260:Female; D006801:Humans; D007509:Irritants / Q000494:pharmacology*; D008875:Middle Aged; D056910:Republic of Korea; D012189:Retrospective Studies; D012882:Skin Tests; D055815:Young Adult
chemical_list: D003358:Cosmetics; D007509:Irritants
keywords: safety testing; sensitive skin/inflammation/Allergy; statistics