I have one of those stack and store containers too.
Mine holds 50 pounds of dry dog and I keep it
inside in our service porch.
Rachel, If you keep it inside where the sun doesn't get
to the plastic and the plastic is in good shape, I
would think it would be fine.
I have heard some dogs have problems with plastic water bowls,
so I change my outside plastic water bowls every 2 years
when they start getting weathered and scratched up.

(I never really thought about the different types of plastic?)