Can Dented Cans Cause Botulism?

The CDC says common sources of botulism are homemade foods that have been improperly canned, preserved or fermented, and that, though uncommon, store-bought foods also can be contaminated with botulinum toxin. It says signs that home-canned or store-bought food might be contaminated with toxins or harmful germs include a container that is leaking, bulging or swollen, a container that looks damaged, cracked or abnormal, a container that spurts liquid or foam when opened, and food that is discolored, moldy or smells bad, and that a container or food with any of these signs should be thrown out.

Do not taste it. The CDC says you cannot see, smell or taste the toxin that causes botulism, and that taking even a small taste of food containing the toxin can be deadly. It says if in doubt, throw it out, and never taste food to see if it is safe.

The FDA describes can damage as swelling, leakage, punctures, holes, fractures, extensive deep rusting, or crushing or denting severe enough to prevent normal stacking or opening with a manual, wheel-type can opener, and says stickiness on the outside of cans may indicate a leak. It says newly purchased cans that appear to be leaking should be returned to the store for a refund or exchange, and otherwise thrown away.