U 1250 (OTTO) Undecylenic acid, 96% Cas 112-38-9 - used as musk in perfumes and aromas. U 1250 (OTTO) Undecylenic acid, 96% Cas 112-38-9 - used for the preparation of active pharmaceutical ingredients, cosmetics, perfumes, antidandruff shampoos and antimicrobial powders.