As government mandates require the increasing use of renewable fuel sources, it is necessary to consider the potential effects of this transition on our existing petroleum retail infrastructure.  Unfortunately, attempting to replace a fuel that has served as the backbone of the American economy for over 100 years will not be easy.  Infrastructure has been developed and engineered to near-perfection for use with two particular fuels, and determining this infrastructure’s compatibility with a new fuel is not something that can happen overnight.  Almost all components typically found at a gas station are mandated by law to be compatible with the fuel used and/or listed by a nationally-recognized third party testing laboratory (i.e., UL).  For new equipment, these requirements are less of an issue, but problems can arise with older components currently installed at gas stations across the country.  Using biofuels in older components without meeting the EPA, OSHA and other requirements can place the retailer out of compliance with federal regulations.  A retailer may be out of compliance with locally-enacted fire codes as well.  Significant work is currently being undertaken to ensure that mid-level ethanol blends can be stored and dispensed in compliance with applicable regulations and codes and with the same level of protections that gasoline and diesel are today.  Similar research will be needed in the future for more advanced biofuels.