Talk:Respiratory system
Carbon dioxide[change source]
Carbon dioxide is not a poison, just a waste-product which needs to be exchanged for oxygen. Carbon monoxide is a poison, and a fatal one, because it binds with haemoglobin strongly. Poison is rather a flexible term, but it is not used by En wiki in this context. Macdonald-ross (talk) 13:31, 10 February 2015 (UTC)