Foodsafe is one of those words we keep bumping into. What does it mean, exactly? Well, we're pretty certain there is an official international standard, complete with a number of specifications, but basically it means you can use the produce for purposes of human consumption. You can eat with it.
"But it's just plastic coming out of my MakerBot/BFB/RepRap - why can't I drink out of the cup I just printed?"
There's a couple of major problems. First, the plastic itself must be safe. While you might think you're drinking tea, minute quantities of the plastic may dissolve or mechanically break off and make their way down your gullet. Are those bits safe? How much material will you ingest if you drink a hot liquid? Where did you get that plastic filament from, anyway? Hm.
The second problem is cleaning. After you've downed a cupful of Lowfat milk you'll have to wash the cup. But current personal 3D printing tech doesn't have perfect resolution and even the nicest prints have grooved lines on their surfaces. Imagine cleaning that perfectly so that no trace of the previous ingestion remains. Not so easy.
So for now, we're printing cups just for show.