People in residential areas where homes are heated with coal, oil, or wood may be exposed to mixed cresols in the air. Some foods, such as tomatoes, ketchup, asparagus, cheeses, butter, bacon, and smoked foods, as well as beverages, such as red wine, raw and roasted coffee and black tea, contain mixed cresols.
Mixed cresols are also strong dermal irritants.
Ingestion of mixed cresols by humans has resulted in death, with effects on the respiratory system, gastrointestinal system, blood, liver, kidney, and central nervous system. Animal studies have reported respiratory tract and eye irritation, and effects on the liver, kidney, and central nervous system from acute inhalation exposure to mixed cresols. Animal studies have reported effects on the blood, liver, kidney, and CNS, as well as reduced body weight, from oral exposure to mixed cresols. Animal studies have reported developmental effects, but only at maternally toxic doses, and no reproductive effects from oral exposure to mixed cresols. Mixed cresols are colorless solids, but usually they occur as a brown liquid mixture.