Foodborne Illness and Food Safety Hazards
What you must know
Food safety hazards fall into three families: biological (bacteria, viruses, parasites, toxins), chemical (cleaning agents, pesticides, allergens, toxic metals), and physical (glass, bone, metal, jewelry). Biological hazards cause the most foodborne illness, and the five big risk factors the FDA ties to operator behavior are: unsafe sources, poor personal hygiene, cross-contamination, time/temperature abuse, and improper cleaning/sanitizing.
Know the difference between infection (live pathogen, e.g., Salmonella, Norovirus) and intoxication (preformed toxin, e.g., Staphylococcus aureus, Bacillus cereus emetic type). Toxin-mediated illness often has a fast onset (1–6 hours) and vomiting; infections typically have longer incubation (12 hours to days). Recognize high-risk populations: pregnant women (Listeria), infants/elderly (general), and immunocompromised guests.
Traps
Questions love to blur foodborne illness vs. foodborne injury (a physical hazard such as glass is injury, not illness). Another trap: naming the source of an outbreak when the stem asks for the risk factor. Norovirus is the most common cause of foodborne illness from a person, not from poultry. Also, allergens are legally a chemical hazard even though they behave like a separate category.
Rule of thumb
If the symptom is vomiting within a few hours and several people who ate the same food get sick, suspect a preformed toxin (Staph or Bacillus cereus); if symptoms are fever/diarrhea after a day or more, suspect an infection.