Hi John, I haven't heard of this before but I did a quick search of the net and came up with the following web site.

Copy and paste this into your browser and I think it will answer your question!

http://www.allotment.org.uk/garden-diary/257/aminopyralid-herbicide-residue-in-manure-killing-crops/

It certainly sounds like you won't be able to use it but I'll leave it up to you!

Thank you for finding the website Ian. Another page on the same website says that it is possible to treat the manure to encourage microbial action to break down the aminopyralid but it is a long process which involves lots of rotovating or digging.
http://www.allotment.org.uk/garden-diary/273/aminopyralid-contaminated-manure/

I think the short answer John is "no". It would probably take longer than the few months between digging in and planting out for the aminopyralid to break down. It looks as if not all plants are affected by it - I wonder if sweetcorn would be immune to it. Mind you, that would just prolong its presence in the environment so that the sweetcorn leaves and stalks contained it. I don't think I'd knowingly eat the cobs either. :-/

You could use in your flower garden would not recommend anywhere near anything you plan on eating though - oh and welcome to GoY John :-)

Though you couldn't grow Solanum species presumably. It looks as though it would be a matter of luck if you try to grow flowers - some may be susceptible to aminopyralid and others may not.

Yes it could still be risky even on flower beds.