I expect most would count baking and candy making among "food prep." the latter of which routinely reaches temperatures around 200-300°F. If stirring a mixture of boiling sugar for 20 minutes at 230°F exceeds the expected food-safety threshold, it seems like there shouldn't be as casual a usage of terms as this:

> If you are using them once heated, this is not always as true (and regulations vary a bit), but if we are talking about food prep/salad/you name it, they are all safe.