Acetaldehyde is an industrial chemical as well as a natural chemical. It is used in the manufacture of perfumes, flavors, aniline dyes, plastics, synthetic rubber and many other items. In nature it shows up in most fruits and vegetables and all fermented products. Acetaldehyde has a general narcotic manifestation with all the symptoms. The chemical is thought to be an important toxic by-product of Candida. It is also volatile in some conditions and as such has free-radical properties. A free radical contributes to the petrochemical sensitivity problem and the spreading phenomenon of allergies to foods. The symptoms it can create are extremely numerous and include respiratory and mental symptoms.