FACT:  The American Lung Association of Metropolitan Chicago credits ethanol-blended reformulated gasoline with reducing smog-forming emissions by 25% since 1990.

FACT:  Ethanol reduces tailpipe carbon monoxide emissions by as much as 30%, toxics content by 13% (mass) and 21% (potency), and tailpipe fine particulate matter (PM) emissions by 50%.

Ethanol also reduces secondary PM formation by diluting aromatic content in gasoline.  Over half of the air pollution attributable to vehicles comes from "high emitting" vehicles that make up only 10% of the vehicle fleet. High emitters include older vehicles as well as well as newer cars with malfunctioning pollution control systems. The use of ethanol-blended fuel is also one of the best pollution control strategies for off-road vehicles, including motorcycles, ATVs and snowmobiles, which represent a significant source of emissions. Source:  Smog Reyes, February 2004

FACT:  Ethanol is the oxygenate of choice in the federal winter oxygenated fuels program and the reformulated gasoline (RFG) program in cities that exceed public health standards for carbon monoxide and ozone pollution.

FACT:  Ethanol is rapidly biodegraded in surface water, groundwater and soil, and is the safest component in gasoline today.

A recent study conducted for the Governors' Ethanol Coalition, "The Fate and Transport of Ethanol-Blended Gasoline in the Environment," concluded that ethanol poses no threat to surface water and ground water. According to the report, ethanol is a naturally occurring substance produced during the fermentation of organic matter and is expected to rapidly biodegrade in essentially all environments. When gasoline contaminates soil or water, ethanol is the first component to quickly, safely, and naturally biodegrade. A study commissioned by the MTBE industry suggested that in the event of a gasoline spill or leak, since ethanol breaks down first, benzene would persist in the environment longer. But this ignores the fact that ethanol-blended fuels contain less benzene, and the real threat posed to the environment is from the presence of benzene in gasoline, not ethanol.


FACT:  Ethanol reduces smog pollution.

Blending ethanol in gasoline dramatically reduces carbon monoxide tailpipe emissions. According to the National Research Council, carbon monoxide emissions are responsible for as much as 20% of smog formation. Additionally, ethanol-blended fuels reduce tailpipe emissions of volatile organic compounds, which readily form ozone in the atmosphere. These reductions more than offset any slight increases of evaporative emissions due to the higher volatility of ethanol-blended fuel. Thus, the use of ethanol plays an important role in smog reduction.

Importantly, in reformulated gasoline areas where smog is of most concern, gasoline blended with ethanol must meet the same evaporative emission standard as gasoline without ethanol. These ethanol blends have the added benefit of providing reduced tailpipe carbon monoxide emissions and, therefore, further emissions reductions of smog.


FACT:  Ethanol has a positive energy balance.

Whether produced from corn or other biomass feedstocks, ethanol generates more energy than used during production. Plants used in ethanol production harness the power of the sun to grow. By releasing the energy stored in corn and other feedstocks, ethanol production utilizes solar energy, replacing fossil energy use. A life cycle analysis of ethanol production - from the field to the vehicle - found that ethanol has a large and growing positive fossil energy balance. According to a 2004 U.S. Department of Agriculture Study, ethanol yields 67% more fossil energy than is used to grow and harvest the grain and process it into ethanol. The study makes note of significant energy efficiency improvements that have been made in ethanol production due to higher yielding corn varieties, technological advances in ethanol production such as the use of molecular sieves and natural gas, and improved farming practices (precision and no-till farming.)

Unlike ethanol, other fuels, including MTBE and gasoline, take more fossil energy to produce than they yield. Importantly, producing ethanol from domestic grains achieves a net gain in a more desirable form of energy. It utilizes abundant domestic energy sources, such as natural gas and coal, to convert grain into a premium liquid fuel. Only about 17% of the energy used to produce ethanol comes from liquid fuels, such as gasoline and diesel fuel.


FACT:  Ethanol reduces formaldehyde emissions.

The California Environmental Policy Committee, in a December 1999 review of the air quality impacts of ethanol, concluded that while the use of ethanol does result in slightly increased levels of acetaldehyde and peroxyacetyl nitrate (PAN), "these compounds are more than offset by reductions in formaldehyde," a toxic air contaminant many times more harmful than acetaldehyde. Furthermore, the Committee concluded other gasoline components are primarily responsible for these emissions. "Other components of gasoline, such as aromatic compounds and olefins, are primarily responsible for the formation of formaldehyde, acetaldehyde, and PAN due to both their greater abundance in gasoline and their shorter atmospheric lifetimes."