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Food and kitchen knowledge

Understanding cross-contamination

How germs and allergens can move between foods, surfaces and hands.

Theory and discussion only · Community education, not accredited training

How our courses work

Learning outcomes

By the end, participants should be able to:

  • Define cross-contamination and allergen cross-contact.
  • Identify common ways contamination can spread in a kitchen.
  • Explain why official guidance keeps raw and ready-to-eat foods separate.

The lesson

Germs don’t always stay where they start. This course explains how germs, and allergens, can move between foods, hands and surfaces, and how official guidance keeps them apart.

01

What cross-contamination means

Cross-contamination is when bacteria or viruses pass from one food or surface onto another food. The Food Safety Information Council calls it a major way that foodborne illness spreads.

It can happen without anyone noticing. Germs can travel on hands, chopping boards and knives, or in juices that drip from raw meat onto other food.

Source:Food Safety Information Council — Food safety tips (opens in a new tab)

02

Raw and ready-to-eat foods

Ready-to-eat foods are eaten without further cooking, such as salads, fruit and cooked meats. Cooking kills germs on raw food, but nothing kills germs that reach a ready-to-eat food before it is eaten. That is why guidance keeps the two apart.

FSANZ names raw meat, poultry, seafood and eggs as sources of germs that can spread to other foods. The Food Safety Information Council adds soil-covered vegetables, such as unwashed potatoes, and advises treating all raw food as if it were contaminated.

Source:Food Standards Australia New Zealand — Food safety basics (opens in a new tab)Food Safety Information Council — Food safety tips (opens in a new tab)

03

Hands, surfaces, utensils and cloths

Hands, benches, chopping boards, knives and plates can all carry germs from raw food to ready-to-eat food. FSANZ advises cleaning benches, boards, utensils and dishes with hot, soapy water before, during and after cooking.

Cloths matter too. Safe Food Victoria says hands should never be dried on a tea towel or on clothes. FSANZ’s guidance for charities describes cleaning utensils in three steps, washing, sanitising and drying, with air-drying best.

  • Separate boards and knives for raw meat and for foods eaten uncooked
  • Never put cooked meat on a plate that held raw meat
  • Wash hands between handling raw and ready-to-eat food
  • Replace boards that are badly worn or have hard-to-clean grooves

Source:Food Standards Australia New Zealand — Food safety basics (opens in a new tab)Food Standards Australia New Zealand — Health and hygiene – advice for food handlers (opens in a new tab)Safe Food Victoria — Personal hygiene for food handlers (opens in a new tab)Food Standards Australia New Zealand — Information for charities and community organisations (opens in a new tab)Food Safety Information Council — Food safety tips (opens in a new tab)

04

Allergens and cross-contact

Allergen cross-contact is the term used when a food allergen gets into a food that isn’t meant to contain it. It is a close cousin of cross-contamination, but it is about allergens rather than germs.

FSANZ explains that the main food allergens must be declared on labels whenever they are present, however small the amount. The Food allergy awareness course looks at allergens more closely. Advice about any person’s allergy must come from a qualified practitioner.

Source:Food Standards Australia New Zealand — Food allergies and intolerances (opens in a new tab)

05

How kitchens are organised to reduce risk

Kitchens reduce risk by giving raw and ready-to-eat foods their own space and their own tools. Official guidance describes several common ways of doing this, in storage and during preparation.

FSANZ’s guidance for charities adds that cooked and ready-to-eat food should go onto clean, dry serving dishes.

  • Ready-to-eat food stored above raw food in the fridge
  • Raw meat, poultry and seafood in sealed or leak-proof containers
  • Stored food kept covered
  • Separate utensils for raw and ready-to-eat food, or cleaned, sanitised and dried between
  • Gloves used for one task only, then changed

Source:Food Safety Information Council — Food safety tips (opens in a new tab)Food Standards Australia New Zealand — Storing food safely (opens in a new tab)Food Standards Australia New Zealand — Information for charities and community organisations (opens in a new tab)

Key takeaways

  1. 01

    Cross-contamination is when germs pass from one food or surface onto another food.

  2. 02

    Raw and ready-to-eat foods are kept apart because ready-to-eat food isn’t cooked again.

  3. 03

    Allergens must be declared on labels however small the amount; allergy advice comes from qualified practitioners.

Talk it over

  • Where in a kitchen do you think germs are most likely to travel unnoticed?
  • How are raw and cooked foods kept apart in kitchens you have known?
  • Why might cross-contamination be more likely when many people cook together?
  • How could a group make sure everyone knows which boards or utensils are for raw food?

Reflect

  • Which idea about keeping foods apart was new to you?
  • Think about a kitchen you know well. How is it organised, and what does that organisation protect against?