What causes a food can to bulge?

Answer 1

The most common food borne illness from canned foods is botulism. This is especially true for canned food with low acid (asparagus, beet, corn).

This is caused by cans contaminated with Clostridium botulinum. The organism releases a botulism toxin and if ingested it brings about symptoms such as: blurred vision, drooping eyelids, slurred speech, dry mouth and muscle weakness.

Answer 2

Botulism. It is deadly, you should never open or eat food from a bulging or swollen can.

Answer 3

Spoilage. Throw it away.