ABSTRACT
3-Methyl-5-(2,2,3-trimethyl-3-cyclopentenyl)pent-4-en-2-ol is a colorless to pale yellow clear liquid; its odor type is woody and its odor at 10% in dipropylene glycol is described as ‘sandalwood woody musk’. The Scientific Committee on Consumer Safety, in a 2012 Opinion on Fragrance allergens in cosmetic products, has marked 3-methyl-5-(2,2,3-trimethyl-3-cyclopentenyl)pent-4-en-2-ol as ‘established contact allergen in humans’. Studies in which 3-methyl-5-(2,2,3-trimethyl-3-cyclopentenyl)pent-4-en-2-ol was patch tested in consecutive patients suspected of contact dermatitis with positive results. In 2000, in Japan, some European countries and the USA, a group of 178 patients with known fragrance sensitivity were patch tested with 3-methyl-5-(2,2,3-trimethyl-3-cyclopentenyl)pent-4-en-2-ol 5% pet. In neither study was the relevance of the positive reactions mentioned.
