Food Contamination

Food is contaminated if it contains something harmful or objectionable. Contamination may occur in a number of ways and cause illness, injury or make the food unfit for consumption.


Foreign bodies in food are physical contaminants that should not be there. Some are dangerous, all are unpleasant and all are unwanted. They are a frequent cause of customer complaint.

• Cigarette ends
• Flies and insects
• Nuts, bolts and washers etc..
• Jewellery


Chemicals may enter the food chain from a variety of sources, e.g. mercury in sea water getting into shellfish, cleaning chemicals being used at the wrong strengths or getting into food accidentally.

Pesticides and lubricants used in food production may also find their way into the food chain. The FSA has set acceptable limits for certain chemicals to be found in food and still maintain food safety.


The most common form of contamination is biological.

• Bacteria are found everywhere: on people, pests, dirt and dust, all raw foods and contaminated water. Food can be contaminated with bacteria but will often not smell, taste or look any different to food that has not be contaminated.

• Viruses most commonly enter food from contaminated water and multiple inside the body causing illness.

• Moulds and Yeasts can contaminate and grow on a wide range of foods. Most of us will have seen mould growing on food, changing its smell and visual appearance and making it unfit to eat.

Naturally Poisonous Foods

Green potatoes, rhubarb leaves and toxins found in raw or under cooked red kidney beans and other pulses can cause illness, although they are not often the cause of illness in food establishments. Only fish may develop a toxin as part of their natural decomposition.

Food Allergies

Although not strictly food poisoning problem certain foods can produce serious life threatening reactions in some people.

Many common foods such as:

• Shellfish
• Peanuts
• Nut Products
• Sesame seeds
• Milk
• Soya
• Fish

Are known to cause allergic reactions. It is estimated that 1-2% of the UK adult population suffer from a food allergy and this figure is even higher for children.

If you want to learn more about Food Hygiene then please visit our Food Course page for more information.

Posted on February 9th 2012

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