Cellphones that detect Chemical and Biological warfare agents? Really?
It will make everyone like Syndrome from The Incredibles!
This is a piss poor idea for like a thousand different reasons. Just to name a few - Chem/Bio detectors are notorious for false positives; having a phone that constantly updates "authorities" is a terrible idea that doesn't even need to be explained; and even if the phone can accurately detect vapors from GB amongst all that Drakkar Noir that you hosed yourself down with, you would be dead before the phone hit the floor.
But hey, who doesn't want a James Bond phone, right?