Kitchen

[Taffytx]

I bought the snowman pattern mugs and have stored them since last Christmas. I just now opened them and the mugs on the bottom rim that is not glazed has quite a bit of powder on all of them. Some of it was in the bottom of the plastic storage container itself. I had them all separated with bubble wrap but not completely encased so that got air to them. Does anyone have any idea what is happening to the mugs and how I can prevent it again this year when I store them after Christmas. Also, after washing these mugs, would there be a health problem using them?