Boat Owners Assn. of The United States (BoatUS), the nation’s largest boat owners group, has come out against raising standard transportation gasoline to a 15% ethanol blend.

According to BoatUS Vice President of Government Affairs, Margaret Podlich, “To add 50% more ethanol to every gallon of gas without first knowing what it will do to the older vehicles and other gasoline engines we currently own, is simply irresponsible.”

The US Coast Guard Office of Boating Safety has also raised concerns about higher levels of ethanol and the lack of independent testing.

Ethanol, a strong solvent, can accelerate the deterioration of fuel system components such as fuel lines, causing them to fail and increasing the level of risk for fire or explosions. The EPA is currently considering a request from ethanol producers to raise the level of ethanol allowed in standard transportation gasoline to rise from 10% to 15% (E15).

In November, EPA officials said preliminary testing is showing no ill effects on autos built later than 2000, and that the agency would likely rule on the request by late summer 2010. However, a January report from the Congressional Research Service (CRS), notes that the EPA’s November response letter “Made no comment on the status of testing for older vehicles or for non-road engines.”

The CRS report also says, “Currently, no automaker warranties its vehicles to use gasoline higher than 10% ethanol,” and “small engine manufacturers similarly limit the allowable level of ethanol.” According to the CRS, it’s unclear if the current fuel distribution systems—pumps, tanks, gas lines, etc.—can tolerate blends higher than E10. “Even if the fuel is approved by EPA for use in motor vehicles, presumably fuel suppliers could be unwilling to sell the fuel unless they are confident that it will not damage their existing systems or lead to liability issues in the future,” the CRS reports.

The CRS report includes an ominous statement from the independent certification and testing company Underwriters Laboratories: “Under normal business conditions E10 at the dispenser (fuel pump) can vary from about 7%-13% ethanol. Assuming a similar variance would exist for E15, it likely under normal conditions ethanol concentrations would exceed the 15% limit.”

BoatUS is a member of AllSAFE, the Alliance for a Safe Alternative Fuels Environment, which includes the Outdoor Power Equipment Institute (OPEI). Officials with AllSAFE urge anyone who is concerned about a higher percentage of ethanol in gasoline and the lack of testing to contact their members of Congress.