Foodborne Illness and Food Safety Hazards
What the exam tests
Domain 1 tests hazard recognition: how contamination becomes foodborne illness and which controls break the chain. Sri Lanka's warm, humid climate makes time-temperature abuse and unsafe water common contributors.
Hazard types
- Biological: bacteria, viruses, parasites and moulds. Examples include Salmonella, Campylobacter, Staphylococcus aureus, Bacillus cereus, Vibrio cholerae and hepatitis A virus.
- Chemical: cleaning agents, pesticides, veterinary residues, allergens and natural toxins.
- Physical: glass, metal, stones, bones, hair and packaging.
Conditions for bacterial growth
Bacteria need food, moisture, warmth, time and a suitable pH. High-risk foods include cooked rice, meat, poultry, seafood, eggs, dairy, gravies and cut fruit. Keep these out of the danger zone and prevent recontamination after cooking.
Worked example
A hotel cooks a large pot of rice at 2 pm, leaves it covered on the counter until 9 pm, then reheats it for fried rice. The rice has spent hours in the danger zone. Bacillus cereus spores survive cooking, germinate and produce an emetic toxin. Reheating kills bacterial cells but not the heat-stable toxin. Correct control: cool the rice quickly in shallow containers, refrigerate, and if reheating, heat to at least 74°C and serve immediately.
Traps that cost marks
- Assuming smell, taste or appearance proves safety; toxins can be odourless.
- Believing freezing kills bacteria; it only stops growth.
- Believing reheating makes any food safe; heat-stable toxins remain.
- Ignoring reporting: suspected outbreaks and illnesses should be reported to the MOH/PHI.