I bet if you fished out every mountain house foil bag that has been burned by you Rosinbag it wouldn't fill an office trash can half full and the aluminum in the constantly burned fire pits in parks get fished out once a year. Obviously not a huge problem. Eventually they will corrode away anyway. Like was said earlier , burn it hot and it will be fine. Not burning it means having to store a bear attractant in your pack and manage when you camp. Cooked food residue smells much stronger than vacuum packed freeze dried does. To all you tree huggers driving your new prius with its colossal energy consuming to make battery and huge toxic waste when it needs to be disposed environmental disaster all I can say is get over yourselves.
And for those worried about all the pollution. Have you added in the waste and pollution caused by transportation of the trash , the filling of a landfill , the burning in an incinerator ? Instead of crying us a river over a minute amount of unburned residue and foil left go work on making a biodegradable and nontoxic to burn alternative at an equal or less cost. Make an equivalent function environmentally friendly bag and I'm all for it .