The Food and Drug Administration (FDA) states that food-borne illness is the leading food safety concern because cases of food poisoning far outnumber any other episodes of food contamination.

Almost every single person in the world experiences a food-borne illness at least once a year. Many don't realize they've experienced a bout of food poisoning, however, because the symptoms are mistaken for the "stomach flu". About 6.5 million cases of food poisoning are reported each year in the United States alone with a higher incidence in the summer months, and for about 9,000 individuals, the food poisoning leads to death.

There are three general types of foodborne illnesses:

1. Infection: occurs when live bacterial cells are ingested. These bacterial cells can then grow in the digestive tract and cause symptoms. An example of a bacterial infection is Salmonella infection.
2. Intoxication: occurs from eating a food that contains a toxin produced by bacteria. An example of food intoxication is Clostridium botulinum poisoning.
3. Intoxification: occurs when live bacterial cells are ingested which then produce toxins in the body. An example of food intoxification is Clostridium perfringens.