The health affects of the chemical are still disputed. MTBE has been shown to cause cancer in lab animals when ingested at levels 20,000 to 100,000 times higher than the U.S. Environmental Protection Agency's drinking water standard. Other animal studies have found that it adversely affects the central nervous system, kidneys and fetal development. A growing body of anecdotal information suggests MTBE could increase the incidence of asthma and other respiratory problems in humans. Some people have complained its fumes cause dizziness and headaches as well as eye, nose and throat irritation.
Inhalation is the most common form of ingestion among humans.
The chemical doesn't accumulate in the body. It is broken down and removed. Avoid overfilling your gas tank when fueling at a service station. Even a small amount of gasoline spilled onto the ground can contribute to water contamination, experts say. Be careful when filling lawn mowers and other gas-powered motors on your property.