When I was commuting to an office job I kept a few EDC items in my leather briefcase - a FAK, a neck lanyard with whistle, knife and bright LED light, mini prybar and a face mask. They were flat enough to be unnoticeable in an inside pocket, and the main thought was to have the minimal stuff that would get me (and others) out of the building in case of fire, earthquake, etc.

I still kept a BOB and other stuff in the car. Always have a Delica 4 in my pocket along with wallet, keys and photon light.