抄録
A closed patch test is one of the most important method to assess the safeties of cosmetics. But considering about the primary irritation of a shampoo, 24 hours or 48 hours contact is very severe to the human skin and gives suffer to the subject. in this report patches were removed 5 and 20 hours. the rsults show there are rank correlation between 5 hours and 20 hours closed patch test. it is enough to get a decision of safety of a shampoo by 5 hours instead of 20 hours patch contact.
