Methyl tert-butyl ether (MTBE)

Methyl tert-butyl ether (MTBE) was synthesized in the 1970s and rapidly adopted as a gasoline additive following the 1973 oil crisis and subsequent environmental regulations [1]. Introduced to increase octane ratings and reduce emissions, MTBE became widely used in reformulated gasoline throughout the 1980s and 1990s. However, by the late 1990s, MTBE contamination of groundwater and drinking water supplies became a major public health concern, detected in aquifers across North America, Europe, and Asia [2]. Its chemical properties—high solubility and persistence in water—made it an ideal tracer of gasoline spills and leaking underground storage tanks. Thousands of water systems reported MTBE contamination, leading to costly remediation efforts and eventual phase-outs in many countries. Today, MTBE remains a significant legacy contaminant in groundwater despite reduced gasoline use and regulatory restrictions [3].

Primary exposure to MTBE occurs through contaminated drinking water, particularly in communities near gas stations, refineries, or in regions with aging underground fuel storage tank infrastructure. Occupational exposure occurs in petroleum refining and fuel production. Inhalation exposure is possible during fuel handling and in areas with high vehicle traffic.

MTBE causes water contamination at extremely low concentrations, affecting taste and odor even at parts-per-billion levels. Health studies link MTBE exposure to liver and kidney damage, nervous system effects, and potential cancer risk. Animal studies showed tumor formation at elevated doses. Contaminated water supplies affecting millions of people created significant public health challenges and remediation costs.

Communities relying on groundwater wells in petroleum-contaminated regions face highest exposure risk. People living near gas stations and refineries experience elevated water contamination. Workers in petroleum production and refining encounter occupational exposure. Children and individuals with compromised immune systems are more susceptible to health effects.