Merlin ... LOL! You must have loved the OJ trial.
The test for phthalates (typical plasticizers) is a piece of cake and can be extremely accurate so the analytical side of this one is easy. Of course now he's going to say he stores all his food at home, for weeks at a time, in tupperware containers in the fridge.
(Actually, tupperware probably wouldn't do it to significant levels, but you get the idea.)