Gas chamber carbon monoxide as the lethal agent. Sometimes a box filled with anesthetic gas is used to anesthetize small animals for surgery or euthanasia. Gas chamber A gas chamber is an apparatus for killing humans or other animals with gas, consisting of a sealed chamber into which a poisonous or asphyxiant gas is introduced. The most commonly used poisonous agent is hydrogen cyanide; carbon dioxide and carbon monoxide have also been used. Gas chambers were used as a method of execution for condemned prisoners in the United States beginning in the 1920s and continue to be a legal execution method in
Exhaust gas the European Union's man-made CO emissions, with passenger cars contributing about 12%. European emission standards limit the CO emissions of new passenger cars and light vehicles. The European Union average new car CO emissions figure dropped by 5.4% in the year to the first quarter of 2010, down to 145.6 g/km. Vehicle exhaust contains much water vapour. There has been research into ways that troops in deserts can recover drinkable water from their vehicles' exhaust gases. Emission standards focus on reducing pollutants contained in the exhaust gases from vehicles as well as from industrial flue gas stacks and other air