Silo gas, formed as newly stored silage ferments, can cause serious injuries -- severe respiratory distress, permanent damage to lungs, and even death. In late summer and early fall, when silos are being filled, the danger is at its peak. "Corn silage forms more silo gas than other crops. We have had incidents of silo gas exposure from haylage, however, so we always need to be concerned," said Mark Purschwitz, University of Wisconsin-Extension Agricultural Safety and Health Specialist. "Wisconsin had a silo-gas fatality last year and apparently one already this year."
Silo gas begins to form immediately after forage is put into a silo. Silo gas includes nitrogen oxide, which changes to nitrogen dioxide, NO2, in the presence of oxygen. Nitrogen dioxide, not to be confused with nitrous oxide or "laughing gas", is a highly corrosive, toxic gas, which forms nitric acid when mixed with water. It is heavier than air and displaces oxygen. Silo gas also contains carbon dioxide, which is not toxic, but is heavier than air and displaces oxygen. When inhaled, the nitrogen dioxide in silo gas mixes with the moisture in the body, forming nitric acid. This causes severe burning and scarring of the lungs and other parts of the respiratory system. Since it is heavier than air, silo gas will settle on the surface of the silage and flow down silo chutes.
People exposed to silo gas may collapse and die from the gas or lack of oxygen. They may go into respiratory distress, fall down the silo chute, or receive respiratory burns. "Victims of silo gas have been known to die many hours later, sometimes in their sleep, from pulmonary edema, the buildup of fluid in the lungs from the burning," adds Purschwitz.
Anyone who has been exposed to silo gas should get fresh air immediately and see a doctor, even if they feel better after getting fresh air. To prevent silo gas exposure, the following steps are recommended:
For more information contact Mike Rankin