Quinoline is a colorless hygroscopic liquid with a pungent odor. It darkens with age. It is soluble in alcohol, ether, benzene and carbon disulfide, and is slightly soluble in water. It is used as a solvent and a decarboxylation reagent, and as a raw material in manufacturing dyes, antiseptics, fungicides, niacins and pharmaceuticals. The occupational exposure to quinoline applies to a person involved in the production of the substance or using products manufactured from this substance. The primary routes of potential human exposure to quinoline are ingestion, inhalation, and dermal contact. The most common symptoms of poisoning include eye and skin irritation, damage to the cornea, the retina or optic nerve, headaches and dizziness. Quinoline produced mutations in bacteria in the presence of metabolic activation, unscheduled DNA synthesis in rat hepatocytes, and DNA adducts. Studies of carcinogenicity in animals indicated that administration of quinoline (in feed) increased significantly the incidence of vascular tumors (hemangiomas or hemangiosarcomas) of the liver. Quinoline is classifield as mutagenic category 2 (substance, which is consider as mutagenic to humans) and to category 1B of carcinogenic substances (potent carcinogen to humans – may cause cancer). According to the above data, the MAC value for quinoline was established at 0.6 mg/m3. MAC- -STEL value was not established. The substance was labeled with “sk” (absorption through the skin can be similarly important as inhalation) and “I” – irritant substance.