emissions. Using E85 also reduces carbon-monoxide emissions and provides significant reductions in emissions of many harmful toxics, including benzene, a known human carcinogen. However, E85 in certain engine operating conditions may increase emissions of acetaldehyde. EPA is conducting additional analysis to expand our understanding of the emissions impacts of E85. Controversy Economics A study by Purdue University found that the economic benefit of E85 is highly dependent on the price of crude oil. Food vs. fuel E85 critics contend that production of ethanol from corn (maize) drives up world food prices, causing corn to be unaffordable or even unavailable. E85 advocates counter that concern by pointing out that over 93% of all corn grown in the United States is never fed directly to people, but is instead used as livestock feed. Corn used to produce ethanol contains a high amount of starch and is not easily digestible by humans, like sweet corn. American farmers grow more corn than people purchase; there is an annual surplus of corn in the U.S. E85 advocates say that corn prices have increased due to manipulation of the commodities markets and because American corn companies sell more and more US-grown corn to Mexico and China, creating more competition for corn buyers, and therefore driving up its price. E85 critics contend that ethanol producers may not reduce carbon emissions due to the petroleum and natural gas used in raising corn and refining it. E85 advocates reply by pointing to ethanol producers who do not do so, but instead use E85 or biodiesel fuel to transport E85, and use biomass as a heat source for the distillation of ethanol instead of petro-products like natural gas. Some say that cellulosic ethanol produced from waste materials or fast growing non-food crops such as switchgrass is much more beneficial, but not yet economically practical at large scale. Others say that the world can easily replace all of its use of petroleum by simply making ethanol from the many crops that yield more ethanol per acre than corn yields, with existing technology, not future technology, and that certain elements in the cellulosic ethanol field are more interested in patent rights than in producing the greatest amount of ethanol at the lowest price point. Availability and price E85 is increasingly common in the United States, mainly in the Midwest where corn is a major crop and is the primary source material for