And, I might add, odorproof bags are already available through Ursack among others. Ursack considers the odor-proof bag an important part of the bear resistance of the Ursack. Of course with the Ursack, the odor-proof bag is inside a tough, fairly light, fabric (and sometimes aluminum-lined) container.

Moreover, as has been noted on this site in the past, odor-proof bags, when handled with hands that have been used to prepare food and other smelly activities, soon obtain an odor on the outside of the bag where any self-respecting bear can detect it. Sorry, this sounds like a good idea in theory but is not one likely to pass the field testing phase.

I have had my share of experience with enterprising Sierra bears and Grand Canyon ring-tail cats, ravens and squirrels. Based on that experience, I seriously doubt that a simple bag, even odor-proof, without a physical barrier will deter any but the dumbest of them.