This bill requires the Office of Research and Development at the Environmental Protection Agency to enter into an agreement with the National Academy of Sciences to provide a comprehensive assessment of research on the implications of the use of mid-level ethanol blends, which compares mid-level ethanol blends to gasoline blends containing 10% or 0% ethanol. A mid-level ethanol blend is an ethanol-gasoline blend containing 10%- 20% of ethanol that is intended to be used in any conventional gasoline-powered motor vehicle or nonroad vehicle or engine. The assessment must: (1) evaluate the environmental, safety, durability, and performance effects of the introduction of mid-level blends on onroad, nonroad, and marine engines, onroad and nonroad vehicles, and related equipment; and (2) identify areas of research, development, and testing necessary to ensure that existing motor fuel infrastructure is not adversely impacted by mid-level ethanol blends and to reduce the risk of misfueling by users at various points in the distribution and supply chain. The office must report on the assessment's findings. Any waivers granted under the Clean Air Act to allow the sale of mid-level ethanol blends for use in motor vehicles are nullified. The office is also prohibited from granting new waivers until after the report is submitted.