This gas has a very offensive odor. The surest way to prevent gas and odor build-up in close confinement hog facilities is to employ the CBPA Waste Management Strategy. Properties and effects of noxious gases Methane is colorless, odorless and lighter than air and is formed by a highly specialized group of bacteria. Generally, conditions found in close confinement hog facilities are not conducive to producing significant amounts of methane. Methane has an explosive characteristic and an asphyxiating effect.
Carbon dioxide is colorless, odorless and heavier than air.
It normally makes up 30 to 60 percent of the gas resulting from decomposition of hog manure. Generally, concentrations of carbon dioxide greater than 4 percent are cause for concern for both humans and livestock. Ammonia is a colorless gas, that makes up a very small percentage of the gases produced during decomposition of animal manure. It is easily recognized by its pungent odor. Ammonia concentrations greater than 0.01 percent in a confinement building are likely to cause considerable discomfort to both humans and animals.