We use potato starch ALL the time in our gluten free baking as opposed to corn starch. Our local health food store is called Good Earth, and we can buy potato starch there in the bulk section. When we buy flours/starches in the bulk department, I always worry that the flimsy little bags will get holes. I am happy to be creating less waste, and so I am just careful with them and normally we don't ever have a problem.
One day recently our little Eli was helping us shop at Good Earth. He had a child sized cart that the store provides, and he was pushing our items all around the store. When it was time to put the items up at the check stand, he had to do it unassisted. (He is going through a big "I do it myself" phase.) That was fine, until he decided to grab all three of our bulk flour bags at once. Two of them made it to the check stand, and one of them made it to the floor. The potato starch bag broke open, sending it all over the floor, and even on the black boots and the bottom of the pant legs of the woman in line.
I explained to the checker that our son had made a mess with a flour bag while trying to help, and I apologized to the poor woman in line. They were all really nice about it. It was cleaned up in no time, and we got another bag of potato starch. The woman in line was making comments about how cute our son is and seemed completely cool with everything. That is when the checker asked me if the woman was my mother! I don't know what she was thinking, but I guess the woman was about 30 years my senior and was being extremely nice about the whole thing.
"No, just a poor woman we covered in potato starch," was all I could say!