Final answer:
An employee should alert the manager about a swollen can because it may contain botulism, a potentially fatal toxin created by the bacterium Clostridium botulinum. While better canning procedures have decreased the disease's prevalence, home-canning mistakes can still lead to botulism.
Step-by-step explanation:
An employee should notify the manager immediately if a swollen can is found because the deadly toxin that causes botulism can be inside. The toxin is produced by the anaerobic bacterium Clostridium botulinum, which can thrive in the anaerobic environments provided by cans, jars, or packages. Swollen cans may indicate that the food inside is under pressure from gas produced by the bacteria, signaling a high risk for botulism.
Improvements in sterilization and canning procedures have significantly reduced the incidence of botulism. However, if these procedures are not properly followed, such as in home-canning where boiling water is used instead of pressure canning, the spores of Clostridium botulinum can survive and produce the botulinum toxin. This toxin is one of the most lethal neurotoxins known, capable of causing life-threatening illness.