Quote Originally Posted by Gib Etheridge View Post
Also, it is cumulative in the blood stream. A very small amount overnight can add up to too much.
It is cumulative, yes.

Our hemoglobin, which carries oxygen in our blood, has a 250 times greater affinity for CO than O2.
250 times!
And with a half life of about 6 hours, it is ridiculously toxic.
Also odorless, tasteless, and invisible...