Urushiol (pronounce /ʊˈruːʃiɒl/) is an oil found in plants of the Family Anacardiaceae, especially Toxicodendron spp. (e.g. poison oak, poison ivy, and poison sumac). It is also found in the nut shell of cashew fruit (Anacardium occidentale) and in mango sap and the skin of the mango fruit. Breaking the vine of a green mango fruit produces a fine aerosol of sap which causes severe reactions in previously sensitized individuals. It causes an allergic skin rash on contact, known as urushiol-induced contact dermatitis. The name comes from the Japanese word urushi, which denotes a lacquer produced in East Asia from the sap of kiurushi trees (Lacquer Tree). The oxidation and polymerization of urushiol in the tree's sap in the presence of moisture allows it to form a hard lacquer, which is used to produce traditional Chinese and Japanese lacquerwares.