ABS in a large enough diameter that Mr/Ms bear can't get their jaws around, and end caps equally sturdy that cannot be gnawed off, might possibly work or more to the point, for bears that recognize and ignore canisters might dissuade them from trying.

But I'd stress out myself worrying and in required areas it would not be regulation-compliant.

OTOH for places where other, smaller critters are a problem it would be just fine. Plenty of folks lose food to squirrels, raccoons and the like.

Cheers,