Production can be defined as simply as, growing the plants we harvest or raising the animals that we use for food. It takes several steps to get food from farm to fork. We call these steps, “The food production chain”. Contamination can occur at any point along this chain during production, processing, distribution and preparation.

Examples of contamination in production include :

  • A hen’s reproductive organs get infected, the yolk of an egg then becomes contaminated in the hen even before the egg is laid.
  • If the fields are sprayed with contaminated water for irrigation, fruits and vegetables can become contaminated before harvest.
  • Fish in some tropical reefs may acquire a toxin from smaller sea creatures that they consume.


Processing, can be defined as altering plants or animals into what we recognise, and buy as food.  Processing can involve various steps using a variety of foods. For produce, processing can be as simple as cleaning and sorting or even involve basic trimming, slicing, shredding and bagging. Milk is usually processed by pasteurising, but other processes include making cheese. Nuts can be roasted, chopped or ground.

What are the examples of contamination in processing?

  • If contaminated water or ice is used to wash, pack or chill fruits or vegetables the contamination can spread to those items.
  • Peanut butter can become contaminated if roasted peanuts are stored in unclean conditions or come into contact with contaminated raw peanuts.
How Do Foods Become Contaminated


Distribution is the means by which we transport food from farm to processing plants to the consumer or food service facility such a restaurants or hotel kitchens.
This step may involve transporting foods just once, such as trucking produce from a farm to a local farmers markets or it may involve many stages, for example frozen hamburger patties might be transported from a meat processing plant to a large supplier, stored for a few days in the suppliers warehouse, trucked again to a local distribution facility for a restaurant chain and finally delivered to an individual restaurant.

Examples of contamination in distribution:

  • When refrigerated food is left out on a loading dock for too long in warm weather. These could encourage temperatures of a critical range which allow bacteria to grow.
  • Fresh produce can be contaminated if it is loaded into a truck that was not properly cleaned and sanitised after the transporting of animals or animal products.
How Do Foods Become Contaminated


Preparation can be defined as the process of getting foods ready-to-eat.

This step may occur in the kitchen of a restaurant, home or catering facility, involve following a complex recipe with many ingredients, simple heating and serving on a plate or just opening a package and eating the food.

Examples of contamination in food preparation:

  • When staff  do not washing their hands after using the toilet or handling raw meat.
  • If a chef uses a cutting board or knife to cut raw chicken and then uses the same knife or cutting board without washing, to slice tomatoes, this could cause possible cross-contamination from the chicken.
  • Contamination could also occur within a refrigerator, if meat juices get into contact with any other items.
This shows you it is vital to ensure that your food is safe from contamination, by having good hygiene systems. This is where Food Consulting Services  can help you. We offer laboratory testing services  and hygiene audit and consulting services.
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Adrian Carter