VOCs and HAPs

The U.S. Environmental Protection Agency defines volatile organic compounds (VOCs) as "any compound of carbon, excluding carbon monoxide, carbon dioxide, carbonic acid, metallic carbides or carbonates, and ammonium carbonate, which participates in atmospheric photochemical reactions."

VOCs released in the production of ethanol can form particulate matter. According to the EPA, exposure to particles larger than 2.5 micrometers and smaller than 10 micrometers in diameter can increase respiratory symptoms, decrease lung function, aggravate asthma, cause chronic bronchitis and produce irregular heartbeat, nonfatal heart attacks and premature death in people with heart or lung disease.

VOCs also include hazardous air pollutants (HAPs) released in the production of ethanol. The federal Clean Air Act amended in 1990 identified 188 pollutants as HAPs and set emission standards.

With their possible health effects, HAPs created in the production of ethanol include:

• Acetaldehyde: a probable human carcinogen.
• Acrolein: irritating to the eyes, nose, throat, lungs, stomach and skin. The EPA says carcinogenicity can't be determined.
• Formaldehyde: watery eyes, nausea, coughing, chest tightness, wheezing, skin rashes and burning sensations in the eyes, nose and throat.
• 2-furaldehyde: skin, eye and respiratory tract irritation.
• Methanol: headaches, sleep disorders, gastrointestinal problems and optic nerve damage.
• Acetic acid: conjunctivitis, eye and throat irritation, burns eyes, chronic bronchitis and asthma.

Carbon monoxide also is released in the production of ethanol. Its health effects include headache and nausea.