Originally Posted by mikey1003

Interesting that you bring up the other detectors.
Five years ago, after a serious sinus and upper respiratory infection, I lost all sense of smell. (More common than you would imagine: http://www.wrongdiagnosis.com/sym/loss_of_smell.htm )
Recently I was in a building that had a natural gas leak, I could smell nothing.
CO is odorless but Chlorine and several other common chemicals are in and around hotels and public buildings. Every few years we hear about a CO or CL death in a hotel. Last time I remember it involved CO from a pool heater.