Says who, you? There's no contaiminates that I'm aware of that JBII's process fears. They got all sorts of crap that zaps them which I won't get into not because it's material info, but for competitive reasons -- however, most of it is listed on the website anyway.
Of course we're only talking in theory -- in reality it's like asking how does a wind mill handle the air in Antartica because my answer would be -- who cares? There's so much air on the planet all over the place just use the "low hanging fruit" of air right around you. Likewise, there's so much waste plastic who cares?
But for fun, and just in case something accidently gets into the processor, I'm answering you -- the JBII processor can handle just about anything. YOU can fall into the processor by accident on the grease in your hair will come out as fuel while the rest of you is filtered out. ;)