News Release

National Safety Council Issues Public Health Alert To Midwestern Farmers

Itasca, IL - The National Safety Council today issued a public health alert to warn farmers in three Midwestern states of an increased risk of illness and death from exposure to nitrous oxide and nitrogen dioxide gas in farm silos. The increased health risk to farmers is a direct result of drought conditions in parts of Iowa, Minnesota and Nebraska.

"Reports from portions of these three states indicate that drought-stressed corn is being harvested for silage at an increased rate over the past few weeks," said Dr. Sam Steel, an agricultural safety expert with the National Safety Council. "Under the late summer drought conditions found in some of these regions, the vegetative parts of corn plants may contain higher than normal levels of nitrogen. This may translate into more concentrated levels of nitrous oxide and nitrogen dioxide, commonly known as " silo gas".

Steel said that farm families and workers must monitor their exposure to silo gas as crops ferment in a silo. "Fermentation begins within four hours of filling a silo and can continue for up to 10 days," he said. "During this time, workers should not enter an upright silo. Exposed individuals may suffer eye irritation, the onset of fatigue and a nagging cough, or nausea. High levels of silo gas exposure may result in the delayed onset of symptoms, sometimes as long as 30 hours after the initial exposure. In extreme exposure cases, silo gas will induce immediate distress with the possibility of collapse and death within minutes."

The problem may be compounded by a lack of knowledge of some farmers who are primarily grain producers. When confronted with a corn crop that will not provide a decent yield, farmers may choose to harvest the crop for silage. "Many of these farmers have not made silage for quite awhile and may have forgotten about the dangers associated with fermenting corn in an upright silo that has gone unused for several seasons," Steel said.

Safe management practices when dealing with fermenting corn silage include:

• Stay out of recently–filled silos and watch for symptoms of excess silo gas. Silo gas is heavier than air and will quietly move down the ladder chute of an upright silo. A bleach–like odor and the presence of a yellowish-brown gas around the base of a silo are strong indicators of the presence of silo gas. Dead insects and birds at the base of a recently filled silo may also indicate the presence of dangerous silo gas.
• Use a blower to ventilate silos at least 30 minutes prior to entry. If the danger of silo gas still exists, use a respiratory protective device such as a self–contained breathing apparatus (SCBA).
• Never allow children or young family members to climb on or explore silos.
• Keep all doors between the base of a silo and ground level barns closed to limit the amount of silo gas that can enter.

The week of September 21–28 is National Farm Safety and Health Week. The NSC, in partnership with Northeast Iowa Community college, operates the National Education Center for Agriculture Safety in Peosta, Ia. For additional information related to agriculture safety, visit www.nsc.org/farmsafe.htm

The National Safety Council is a nonprofit, nongovernmental, international public service organization dedicated to protecting life and promoting health. Members of include more than 45,000 businesses, labor organizations, schools, public agencies, private groups and individuals. Founded in 1913, and chartered by the U.S. Congress in 1953, the primary focus of the NSC is preventing injuries in workplaces, in transportation and in homes and communities.

For additional information about the National Safety Council, visit www.nsc.org.