If you become trapped in a bin of flowing grain with nothing to hold onto but you are still able to walk, stay near the outside wall. Keep walking until the bin is empty or grain flow stops. Also, if you are covered by flowing grain, cup your hands over your mouth, and take short breaths. This may keep you alive until help arrives. When wet grain is stored it ferments.
Carbon dioxide is heavier than air and pushes it out of the bin.
This results in an oxygen-deficient atmosphere. If you enter a grain bin where carbon dioxide is present, it gets into your bloodstream and slows down your breathing, causing drowsiness, headaches, and even death by suffocation. If you suspect the presence of carbon dioxide in the grain bin, don't go inside. To reduce the hazard, open manholes and all side door openings and force air through the bin. Your local emergency rescue team is trained and has the equipment to help in this type of an emergency.