Ah, I made the assumption that a vegetable oil based plastic would at worst break down or go rancid. And tiny bits of rancid oil wouldn't be harmful. However, if they're using other chemicals to produce these, then it's entirely possible that they would be unsafe. My bad.
I explicitly said that vegetable based plastics are not a problem. What we're worried about are the OXO plastics, which are not vegetable, but mineral oil based.