Dr. Ken Griswold, Pennsylvania State Cooperative Extension Dairy team, urges farmers to take NO2 gas associated with silage seriously. Griswold points out that maximum NO2 production occurs during the first three to five days after the forage is put up, adding that producers should stay out of the silo for 21 days to limit exposure potential.
OSHA lists the permissible exposure limit for NO2 gas at 5 ppm, but does not recommend exposure at greater than 1 ppm. While silo filler's disease is most often associated with upright silos, Griswold says exposure can happen with bunkers too.
- Use a blower to ventilate the silo for a minimum of 30 minutes before entering a silo and keep the doors closed while you're ventilating. If doors are open, it will push the gas toward you in high enough amounts that it can make you collapse.
- Keep the fans running while you're in the silo.
- Do not enter the silo from the top. If you are exposed to silo gas, you will likely be too weak to climb out of the silo.
- If you see or smell gas at any time, get out immediately.
- Always tell someone if you will be working in or around a silo.
--reprinted by permission from the Professional Dairy Producers of Wisconsin