ETHYL TERTIARY BUTYL ETHER (ETBE) AND METHYL TERTIARY BUTYL ETHER (MTBE): STATUS, REVIEW, AND ALTERNATIVE USE
Date of this Version
Petroleum products from leaking underground storage tanks have raised concerns regarding the quality of groundwater resources. Although many of the components of gasollne may be retained in soils by adsorption and eventually degrade, the more water-soluble components such as methyl tert-butyl ether (MTBE) spread through groundwater. Of the 60 volatile organic compounds analyzed in samples of shallow ambient groundwater that were collected from eight urban areas during 1993-94 as part of the U.S. Geological Survey's National Water-Quality Assessment program, MTBE was the second most frequently detected compound. Concerns about MTBE health effects in California alone have reached such a critical point that severai MTBE-related bills were introduced and passed in the California Assembly in 1997. The MTEE-related bills called for health risks assessments of MTBE and other oxygenates and provisions to identify, monitor, and prevent MTBE contamination of drinking water wells. They further require investigations on the health and environmentai risks and benefits of MTBE as compared to ethyl tert-butyl ether (ETBE), tertiary amyl ether (TAME), and ethanol. The concerns about the environmental behavior and fate of MTBE as an oxygenated additive have aiso prompted the National Renewable Energy Laboratory to initiate an investigation to explore the technical characteristics of ETBE in relation to its health effects and in comparison to MTBE. The findings of :his investigation confirm the validity of the MTBE-related concerns. These findings also reveal significant differences between the physical characteristics of MTBE and ETBE.