If sugar acts as a preservative, what is the ratio for buttercream icing so that the health dept. will not make me refrigerate my cupcakes?

That's probably a question for your health department.

Thet want me to research and submit, otherwise they wont approve

I hate to tell you but you probably will get many different opinions on this *even from the different inspectors* in your local health dept

You also might check out Earlene Moor's post on her cream cheese icing. As I remember, she says something about how her recipe passes (at least her local) HD requirements.

Does your HD at least have pH and aW guidelines or ranges they have approved for your area? You might need to have your recipe(s) tested to see if they fall into that range. Where are you located? Does your state have a cottage food law? If they have a website, that may be a good place to get answers to this question since it would be for your area.

I cant find this user or recipe for health d approved icing. Does anyone remember?

Why don't you PM KellyM? She has all that info on a website, something about the Texas cottage food law. You can donate to it, once you find it, because many of the recipes were tested at the bakers own expense.

Also, if you look in the recipes section, some of the icings/buttercreams will say "does not need refrigeration" or "Shelf stable." You may need to validate the claims. Most American BCs that contain no whipped cream or cream cheese tend to be shelf stable like Indydebi's BC and Sugar Shack's BC; tonedna also has a BC.

Of course all of this is assuming that what you're looking for is American BC not a meringue.

One last thing: Google is your friend.
do a search for shelf stable buttercream

Earlene's BCs

http://www.earlenescakes.com/icings.htm