"Now that is interesting considering that probably 95% of our food and liquid is packaged in plastic. Is there something specific about water piping?"

Plastics used for packaging eatables are supposed to be food grade and not the ones that are used for making chairs and TV cabinets ;-) So that should take away the concern that you have. But the story is different with tubes meant to handle water - I dont think they need a "Food Grade" certification.

Raghu