Sewer lines are designed to protect you and your household from the unpleasantness and health risks of the liquid waste generated from your home. But sometimes, the system fails and releases sewer gases plus disgusting sewer gas odors into the home. What causes sewer gas odors in the home and is sewer gas harmful to human health? CAN SEWER GAS HARM YOU? Sewer gas, being a by-product of decomposing household waste contains a complex mix of gases and microorganisms. Some of these gases are harmful to humans and there is a huge possibility that sewer gas may also contain dangerous bacteria, warns Innovative Property Solutions . Gases commonly found in sewer gas are: Hydrogen sulfide This gas is responsible for the rotten egg smell of sewer gas. It is toxic to the oxygen system of the body. Ammonia Ammonia can irritate the eyes, nose, throat, and respiratory tract or result in organ damage and even death. Methane and carbon dioxide Methane is a flammable gas and in large quantities ca...