... Canada, the Canadian Food Inspection Agency has also approved the use of inert gases to kill poultry (CFIA 1999b). According to Anglia Autoflow’s sister company, American Autoflow, Inc., ... slaughterhouses, and according to the European Commission (2003), “[T]here are at least 4 companies in the UK using a predominantly nitrogen based gas mixture for killing chickens and turkeys.” In Canada, ... inert gases to be less aversive to birds than carbon dioxide.” Other studies confirm that birds, as well as humans, can only tolerate carbon dioxide levels up to 30 percent (Gregory and others...