A toxin produced in food by the micro-organism Clostridium botulinum causes botulism. It is found in soil all over the world. The organism has the ability to form a spore very resistant to heat and chemicals. Its toxin is the most deadly we know.
Cases are rare, but each year several outbreaks of individual cases occur.
They include peas, corn, lima beans, green beans, mushrooms, sauces, and soups. The food is canned or processed in some way. Inadequate processing or heating lets spores live and toxins form. Conditions after processing let spores grow and toxins form. The food is not heated enough before eating to kill the toxin.