I have a buttercream recipe that contains butter and pasturized egg whites.   How long can a cake decorated with these ingredients stay out of the refrigerator? Does it require refrigeration? I am starting a cottage business and the law in Missouri says that the items cannot require refrigeration. 

I think you are going to have to submit the recipe to your health department.

cant guarantee this but I have been told that the amount of sugar renders it safe — without refrigeration  

How ever my experience with health departments is each inspector has their own interpretation of each rule :( 

very very true what lynne said — even within the same health department like she said, inspectors are not on the same page — gotta ask them

You may use pasteurized egg whites, but once out of the carton, they decompose very quickly if not refrigerated. I will keep the buttercream refrigerated. All of this regarding what your cottage law says!

As others have posted, you really need to check with your local health department. It varies so much for each area where you live. Best of luck