Contamination

Contamination is the introduction or presence of a biological, chemical, physical or allergenic hazard in food, on food-contact surfaces or in the food-handling environment. Contamination can make food unsafe, unsuitable for consumption or non-compliant with food-safety requirements. It may occur at any stage from receiving and storage through preparation, cooking, cooling and service.

Four broad categories of contamination

• Biological: harmful bacteria, viruses, parasites or toxins produced by microorganisms.
• Chemical: cleaning chemicals, pesticides, lubricants, excessive additives or other chemical substances entering food.
• Physical: foreign objects such as glass, metal, plastic, stones or packaging fragments.
• Allergenic: the unintended presence or transfer of an allergenic ingredient or protein.

How contamination occurs in a kitchen

Examples include raw poultry juices contacting ready-to-eat vegetables, sanitizer residue remaining on a food-contact surface, glass breaking near uncovered food, or peanut residue transferring to a meal for an allergic guest. Poor handwashing, inadequate cleaning, damaged packaging and incorrect storage can all contribute.

Preventing contamination

Use approved suppliers, inspect deliveries, separate raw and ready-to-eat foods, maintain personal hygiene, clean and sanitize food-contact surfaces, store chemicals away from food and protect ingredients from foreign objects. Follow allergen-management procedures and keep food covered and properly labelled.

Chef’s tip: When contamination is suspected, isolate the affected food immediately. Do not taste it to assess safety; follow the operation’s disposal, investigation and corrective-action procedures.

Key distinction: Contamination is the presence or transfer of a hazard. Spoilage is a deterioration in quality and does not always indicate the same type of safety risk.