Claim it detects CBRN agents, sell it to the paranoid;
make a fortune from office workers. Particularly if it has a loud integral alert.
On a lighter note, imagine the fun if one on every desk in the cities of London or NY (for example) went off at the same predetermined time ("accidently" left as a test feature in the firmware).
I'm sure it has potential bona fide uses for those with respiratory conditions such as asthma, but we find that if they're breakdancing on the floor, its a good guide to something not being quite right.