There are several ways harmful bacteria can contaminate canned food. In the United States, over 100 cases of botulism are reported each year. A person can’t see or smell if a can is contaminated with botulism spores, however, there are other contaminates that can be seen and smelled. The good news is that most of the signs of spoilage are fairly easy to recognize once you know what to look for.
- A lid the bulges (moves up & down when pushing on it)
- Food projecting or exploding when the can is opened
- Rusting or corrosion of the can
- Dents--cans that are dented on the top or bottom, or near seams, are particularly susceptible. If the can is dented alone the side, it is probably safe to eat as long as it doesn't have any of the other signs of spoilage.
- If the can is dented along the side it will probably be safe to eat the food inside
- Acrid smell
- Rising bubbles or unnatural looking colors
- A loud hissing sound when opened (most cans make a very small hissing sound when opened, but a loud hiss is a sign of spoiled food)
- No sounds of liquid inside the can when shaken
If your canned food has any of these problems, DON'T taste it and handle with care. Contact with a botulinum toxin can be fatal whether it is ingested or enters through the skin. Avoid contact with suspect foods or liquids and carefully dispose of them.
For more information on preventing botulism with home canned/bottled foods, click HERE.