PVC is safe for water or food. It is what brings your drinking water to you, more than likely. It neither leeches toxins
nor absorbs them. There is no such thing as "food grade" PVC as for as I know, and many food stuffs such as flour,
syrup, cake icing, etc. are stored in PVC containers. As far as piping, there are different grades (called schedules) which I believe
relates to strength or wall thickness. It is completely biologically and chemically resistant.