Cresol is the common name for a group of oily chemicals that scientists called hydroxytoluenes. They are used to dissolve other chemicals, and they also serve as an ingredient in some disinfectants and insecticides. Cresols occur naturally, but they may also be manufactured. Natural sources of cresols include certain foods, wood and tobacco smoke, and crude oil. There are three known types of cresols: ortho-cresol, meta-cresol, and para-cresol.