pointless, whats the chance of anyone living within 10 miles of me getting one of them carrier bags.
now I've criticized the Idea

i'll give my suggestion

people from all around the UK will be getting these carrier bags so this is no good for individual companies, but an NCCA leaflet or AllergySTOP leaflet listing all the UK members would work, anyone looking at the leaflet could chose the company most local to them, I'd contact Nick or the NCCA or even Woodman he might like to advertise his website in your bags.
just my thoughts
Mike