Those possible alternatives to MTBE are ethyl tertiary butyl ether, or ETBE, and tertiary amyl methyl ether, or TAME. However, their safety has yet to be determined, Barreto says. "Rather than trying ...

Of particular concern are the fuel oxygenates MTBE (methyl tert-butyl ether) and TAME (tertiary amyl-methyl ether), which are highly mobile and have uncertain biodegradation potential in groundwater.