q & a, page-81

Stupid argument saying Co2 can be toxic.

Oxygen can be toxic too at certain levels.

Too much of a good thing is usually bad for you as well.



'We breathe air that is 21 percent oxygen, and we require oxygen to live. So you might think that breathing 100 percent oxygen would be good for us -- but actually it can be harmful. So, the short answer is, pure oxygen is generally bad, and sometimes toxic.'

http://www.howstuffworks.com/question493.htm