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 was still increasing. The most commonly quoted producer price for natural gas is the Louisiana-based Henry Hub price, which is futures-traded on NYMEX. A barrel of oil releases about 5.8 million BTU when burned, so that 5.8 MCF of gas (at the standard one thousand BTU per cubic foot) releases about the same energy as a barrel of oil. Sometimes gas containing 5.8 million BTU is defined as a "barrel of oil equivalent for energy calculation purposes. When describing reserves or production, however, the oil and gas industry more commonly uses the rounded number of 6 MCF of gas (or