The occupational health problem of synergistic effects arising from exposure to ethanol (64175) in combination with certain chemical agents is reviewed. The prevalence of alcoholic consumption in the American workforce is considered. The metabolism of ethanol is discussed. Compounds which inhibit aldehyde-dehydrogenase (allowing buildup of acetaldehyde in the body) produce toxic effects including tachycardia, decreased diastolic blood pressure, hypertension, increased breathing rate, and symptoms of alcohol induced intoxication. Synergistic actions of thiuram disulfides with ethanol have led to the use of disulfiram (97778) as a prescription drug to discourage alcohol consumption. Other substances that interact with ethanol through aldehyde-dehydrogenase inhibition are also discussed: dimethylformamide (68122), cyanamide (420042), calcium-cyanamide (156627), and N-butyraldoxime (110690). Ethanol also enhances the toxicity of carbon-tetrachloride (56235), trichloroethylene (79016), chloroform (67663), and methylene- chloride (75092). Cobalt (7440484), manganese (7439965), and mercury (7439896) are known to interact with ethanol. Possible synergistic mechanisms, relevant animal and clinical studies, industrial uses, and routes of exposure are discussed for each compound. The role of ethanol in the etiology of cancer is also considered. The authors conclude that both employer and employee are responsible for controlling the problem of synergistic exposures to these chemicals and alcohol. Employee education is suggested to modify drinking habits and to explain synergistic effects of alcohol consumption and occupational exposures.