Nitrogen:
Nitrogen (N2) makes up more than 78 % of the earth's atmosphere. Those will not burn or support combustion. It cannot be detected through any of the senses and it is not toxic. While it is frequently referred to as an inert gas since it does not oxidize readily, it nevertheless forms several compounds. It is often used to inert systems that hold, or have contained, flammable liquids or gases. Inerting a system means replacing the oxygen along with an inert gas in sequence to decrease the possibility of fire or explosion.
Nitrogen is fairly soluble within the blood, and a considerable amount will dissolve within the blood of a person while the air pressure is raise, as in diving, caisson, and a few tunnel works. The dissolved nitrogen escapes from the blood within the form of little bubbles in the bloodstream causing intense pain and is frequent fatal if these employees are not properly decompressed. This disorder is generally known as the bends.
It could cause a serious oxygen deficiency if a huge amount of nitrogen were released within the air of an enclosed space. Nitrogen is an asphyxiant.