It is especially harmful to people with heart disease, chronic lung disease, anemia, and to unborn children. For healthy people, excessive levels of CO can cause headaches, fatigue, slow reflexes, and dizziness. CO reaches unhealthy levels primarily during the winter. Oxygenates are gasoline additives that contain oxygen. MTBE is the most common oxygenate used in gasoline.
Ethanol is used both as a gasoline oxygenate and as a fuel.