PVC stands for Poly Vinyl Chloride. It is a hard plastic. They add something called plasticizers, generally phthalates, to the PVC to make it soft and pliable.
Phthalates leach out easily from PVC. They leach out in contact with water, and especially alcohol. There are some new PVC tubings that are flexible and do not use phthalates, but they are medical grade, I believe, and much much more expensive.
I would be hesitant to use PVC with food.