"First, unlike with hard-sided canisters, bears were able to chew the bags, mutilating the food inside and rendering the food inedible due to the presence of bear saliva. In some instances, the aluminum insert was crushed and torn, resulting in small fragments of metal mixed into the smashed food. The ability of bears to destroy the food was problematic for three reasons. First, backpackers might be inclined to dump their spoiled food, allowing bears access to the food and also contributing to wilderness litter. Second, the presence of bear saliva on the food posed a small risk of rabies infection, and the possibility of a backpacker eating food containing shredded aluminum posed its own safety hazard."
