Err, yes, co2 could be carbon dioxide wouldn't it.
http://www.nfpa.org/categoryList.asp?cat...rbon%20monoxide gives a brief description doesn't it.

All the alarm companies around here are just installers for companies like ADT and such. We had one in the old house but between the false alarms from not being installed properly and them not being able to tell me how they can make the police respond any differently than when I call them myself we ended up turning it off, was
$35 a month for nothing.