Taylor McDonald

Sep 14, 2016  |  Today's News

Almost a month has passed since the Inspector General’s Office of the Environmental Protection Agency (EPA) announced that the EPA has failed in its responsibility to produce research on the impacts of ethanol blending in transportation fuels. While the Renewable Fuel Standard (RFS) has created a biofuels mandate, the inaction of the EPA perpetuates clashing arguments surrounding biofuels without providing an answer. True, many studies about ethanol have already been published that offer conflicting conclusions. Yet, the EPA’s research has the potential to challenge the beliefs of those who oppose biofuels after coming from what is traditionally seen as a non-partisan agency.

Ethanol has the possibility to be one of the most viable fuel alternatives to traditional gasoline. It could help scale back the need for international dependency on crude oil. So the need to clearly understand the impacts of ethanol blending is crucial, especially when the EPA has proposed reducing target blending levels of ethanol that were established by the RFS.

As with any issue, there are myths and rumors about ethanol that are inserted into national discussions that are repeated and normalized until fact and fiction are intertwined.  While misinformation continues to thrive and a non-partisan agency attempts to reduce national ethanol usage without providing any research that RFS legislation mandates in order to back it up, it is important that we educate ourselves and others. Arguments that start on foundations of mutual understanding and fact are often more productive. So here’s refresher on the history of ethanol, courtesy of the Environmental and Energy Study Institute:


Early automakers expressed interest in plant-based alcohol fuels, such as ethanol. Henry Ford designed the first Model T to run on ethanol. But, at the time, gasoline was a much cheaper fuel. Additionally, Standard Oil was “reluctant … to encourage the manufacture and sale of a competitive fuel produced by an industry in no way related to petroleum.” The petroleum industry has controlled the fuels market ever since.

During the 1973 oil embargo, regular unleaded gasoline prices jumped 57 percent and routine gasoline shortages also occurred. These events, and the regulation of many air pollutants, sparked a renewed interest in fuel efficiency, electric vehicles, and renewable fuels such as ethanol, which were seen as ways to meet the new regulations and reduce petroleum consumption. Today, the majority of ethanol in the United States is blended with gasoline to produce E10 (10 percent ethanol, 90 percent gasoline). Over 95 percent of gasoline sold in the United States is E10.

Ethanol as an Octane Booster

In addition to having lower lifecycle greenhouse gas emissions than conventional gasoline, ethanol is an excellent octane provider, with neat (pure) ethanol having an octane rating of over 100. Currently, refiners create ‘sub-octane gas,’ which has a lower octane rating than required. Ethanol, which is generally the cheapest octane provider, is then used to bring the octane rating of the gasoline up to the labelled octane value on the gas pump. For example, 84 octane gasoline is typically blended with 10 percent ethanol to reach the minimum octane requirement of 87 for retail gasoline.

Ethanol & Health Concerns

While ethanol has a higher volatility than gasoline, meaning it vaporizes more quickly, it is a cleaner-burning alternative to petroleum-based octane boosters. Additionally, the toxicity of ethanol is low compared to the health effects of BTEX and its combustion products, such as ultrafine particulates (UFPs) and polycyclic aromatic hydrocarbons (PAHs). A modest increase of ethanol content in fuel from 10 to 15 percent would result in an anticipated 6.6 percent reduction in cancer risk from tailpipe emissions.

There is contradictory evidence that increasing ethanol content in gasoline increases nitrous oxide (NOX) emissions, an ozone precursor. Several studies find either no relationship between ethanol blending and NOX emissions, or find decreased NOX emissions with increasing ethanol volumes. Other studies suggest older cars emit more NOX when using ethanol blends. However, a study of 2012 make and model year vehicles found no increase in NOX emissions between E10, E15 and E20 blends, suggesting that both engine design and engine age play a role in NOX emissions. Overall, the effect of ethanol on NOX and carbon monoxide (CO) emissions is minor in newer engine emission control systems.

Timeline of Ethanol Phase-In

1975: Congress passes the Energy Policy and Conservation Act (EPAct), establishing Corporate Average Fuel Economy (CAFE) standards for cars and trucks.

1988: The Alternative Motor Fuels Act establishes incentives under CAFE for alternative fuel vehicles.

1992: The Energy Policy Act of 1992 defines alternative fuels and establishes programs at the federal level to increase the use and research of alternative fuels.

2005: Congress passes the Energy Policy Act of 2005, establishing the Renewable Fuel Standard (RFS). RFS sets a minimum volume of renewable biofuels to be blended into the transportation fuel supply.

2007: Congress passes the Energy Independence and Security Act (EISA), significantly increasing the volume of renewable fuels mandated under the RFS, to 36 billion gallons by 2022.

2013: Citing a lack of renewable fuels infrastructure, EPA proposes reducing the volume of renewable fuels under the RFS.

2015: The Administration sets renewable fuel volumes for 2014 – 2016. Final renewable fuel volumes for 2016 are 18.11 billion gallons, set at approximately 1 billion gallons higher than the 2013 proposal, and at just over 10 percent of the fuel supply. This includes the categories of renewable fuels, cellulosic biofuels, advanced biofuels and biomass-based diesel.