Im in the process of finding sources for my WVO. The best/biggest source I have is the fast food resturant I worked at when I was in high school. Having been employed there in the past I know that the cooks sometimes will dump the scrapings and grease (animal fat from the burgers) from the grill as well as leftover melted butter in the collection bin. I also know that if I were to provide my own bin and the managers were to instruct the cooks to dump only fryer oil in it there is still the chance that "the new guy" or some PO'd cook wont comply. Will these other oils affect the vegetable oil and can it still be used for BIO, or do I need to give up on this source and attempt to find others?