Food Safety Hazards and Preventive Controls
This domain tests hazard analysis and the logic that turns a significant hazard into a control: process controls (CCPs), allergen controls, sanitation controls, supply-chain controls, and recall plans. Expect questions distinguishing validation from verification and CCPs from other preventive controls.
Hazards
- Biological: Salmonella, Listeria monocytogenes, STEC E. coli, Clostridium botulinum, Bacillus cereus, Staphylococcus aureus toxin, moulds and mycotoxins.
- Chemical: allergens (cross-contact and mislabelling), cleaning chemicals, lubricants, heavy metals, veterinary drug residues, mycotoxins.
- Physical: metal, glass, brittle plastic, bone, stones, wood.
- Radiological (rare but must be considered).
Hazard analysis is severity × likelihood, considering the product, process, intended use, and vulnerable consumers. Only hazards that are reasonably likely to occur and significant need a control.
Control logic
FSMA-style preventive controls include process, allergen, sanitation, supply-chain, and recall plans; a CCP is one type of process preventive control. Every control needs critical limits, monitoring with frequency and responsible person, corrective action, verification, and records. Validation happens before or at implementation (does this control actually achieve the outcome?); verification happens ongoing (is it working as designed? calibration, record review, environmental monitoring).
Worked example
A fresh-cut salad line slices product on a rotating blade before packing. Metal fragments are reasonably likely at low likelihood but serious severity, so metal detection is a process preventive control with critical limits of 1.5 mm ferrous, 2.0 mm non-ferrous, 2.5 mm stainless. The same line switches from a sesame dressing to a plain SKU. The allergen is a chemical hazard requiring an allergen preventive control: validated cleaning, sequencing, and label verification. Failing to validate the cleaning (swab or allergen-specific test) leaves a gap even if the schedule is followed.
Traps that cost marks
- Making every hazard a CCP; over-control obscures real risk.
- Confusing validation (before/at implementation) with verification (ongoing).
- Writing "zero" as a critical limit where a measurable limit exists.
- Treating allergens as a labelling issue only, ignoring cross-contact.
- Using ATP results as evidence that pathogens are absent; ATP measures organic soil.