The three research projects contained in this report were initiated to increase our knowledge of the metabolism of ether oxygenates in humans and other species. Adding oxygenates, such as MTBE (methyl tert-butyl ether), to gasoline promotes more efficient combustion and reduces emission of carbon monoxide, ozone-forming hydrocarbons, and some air toxics, by increasing the oxygen content of the fuel. On the other hand, some oxygenates may increase emission of toxic compounds such as formaldehyde or acetaldehyde, and increased use of MTBE in fuel in the early 1990s led to complaints of unpleasant odor, headaches, and burning of eyes and throat. The studies were conducted by Dr Jun-Yan Hong (the University of Medicine and Dentistry of New Jersey – Robert Wood Johnson Medical School), Dr Wolfgang Dekant (University of Würzburg), and Dr Janet Benson (Lovelace Respiratory Research Institute).