I came looking for the same answers as all of you ladies! From the research that I've been doing, rip stop nylon is safe for dry foods. However, the shiny coated side of the nylon has to be AWAY from the food. I am hoping for some suggestions on where to buy the ripstop nylon in small quantities.
Here's a bit of info on snack bags.
Oh, and I tried/am in the process of trying the beeswax fabric idea. Holy, it's a lot of work to get the beeswax evenly distributed over the fabric and not have too much or too little. Plus, then the fabric just looks and feels greasy (but smells wonderful) and I don't think it's really "sealed" either, so you wouldn't be able to use it with anything wet or anything that can get stale (which makes me sad, because I was actually trying to make a nice bread bag for my homemade bread. Anyway, I've just done the beeswax part so far, and haven't sewn the bag (which I think will have 2 layers, the inner beeswax "sealed" layer and an outer layer to make it look pretty). I'll update with how it turns out/works.