I've recently drawn up several machines that handle food. However I wanted to know if there are any materials that I should stay away from, for handling food. To clarify, I would like to go to a harware store to pick up supplies, but is it ok to run liquids or store food in pvc for example. What about when it comes to liquids. If anyone would like to suggest materials that I could use safely or that I should avoid, I would appreciate it greatly. Thanks.