Polyethers, the main ingredient in polyurethane foams, and propylene glycol are both made using propylene oxide. Propylene oxide has irritated the eyes and respiratory tract in people and animals who have experienced acute (short-term) exposure to it. Even with diluted solutions, dermal contact has led to skin necrosis and irritation in people. In people, propylene oxide has a modest depressive effect on the central nervous system (CNS) Propylene Oxide Market. Animals that were continuously (long-term) exposed to propylene oxide by inhalation showed neurological effects as well as inflammatory lesions of the lungs, trachea, and nasal cavity. In mice, propylene oxide has been shown to induce tumours at or near the site of administration. These tumours have been detected in the nose and stomach after exposure to the chemical through inhalation gavage.