Silo gases can create dangerous conditions in upright silos, says John Smith, an extension agent in Auglaize County, Ohio. For example, when nitric oxide combines with oxygen, the resulting gas — nitrogen dioxide — can result in death or permanent lung damage.

Smith offers the following guidelines to help you work safely around the base of a tower silo during the first few weeks after filling:

1. Stay out of the silo at least two weeks after filling.

2. Keep the door closed between the silo room and the barn.

3. Open outside doors and windows to ventilate the silo room for at least two weeks after filling the silo. Remove chute doors to silage level to permit ventilation.

4. Before you enter a partially-filled silo, run the silage blower for 15 to 20 minutes. Keep the blower running while you are within the structure.

5. Leave the blower pipe at silage level to draw off gas.

6. Always wear a safety harness and make sure someone is nearby when you enter a silo. If gases are present, use an air backpack or another form of supplied air.

7. If you begin to cough or experience throat irritation, get out of the silo at once and seek medical attention.