Inert gas asphyxiation lacks oxygen and consists of an asphyxiant gas (one or more of argon, nitrogen or carbon dioxide), causing the animals to lose consciousness. Argon and nitrogen are important components of a gassing process which seem to cause no pain, and for this reason many consider some types of controlled atmosphere killing more humane than other methods of killing. However, "stunning" is often done using carbon dioxide. If carbon dioxide is used, controlled atmosphere killing is not the same as inert gas asphyxia, because carbon dioxide at high concentrations (above 5%) is not biologically inert, but rather is toxic and also
Natural gas in the United States gas pipelines. The North American market, consisting of Canada, Mexico, and the United States, all connected by a common pipeline network, has had much lower gas prices in recent years than some other major world gas markets, such as Europe (since 2010), Japan (since 2008), and Korea. The United States is connected by pipeline to Canada and Mexico. The US has long imported large quantities of gas from Canada, and exported smaller quantities to some parts of eastern Canada. In 2014, the US imported 2,634 BCF from Canada, and exported 769 BCF, so that net imports from Canada totaled 1,865