In the field of food safety and correct "good food" handling there are four recognized principles by which the food industry regulates how it relates to all issues of food hygiene.

Together, these principles work to cover all critical areas where the contamination of food occurs.

By observing these principles we greatly minimise the hygiene risks involved in the handling of food and in the consequential contamination of food.

The four golden rules of food hygiene are:

Buy food from a safe source. 
Prevent bacteria from entering your food. 
Prevent the multiplication (or growth development) of bacteria in your food. 
Destroy bacteria on food, utensils and work surfaces

Rule No.1)

Buy food from a safe source.

Make sure that you buy food only from a suppliers who are well known and reputable. It is important to check that all (food recipes) be within their expiry date and kept in appropriate conditions in the shop.

Serving counters should be kept spotlessly clean, likewise machines such as mincers, knives and slicing machines.

Freezers, fridges and chillers should display their temperatures and should be set at less than 5 degrees centigrade for chilled products and -18 degrees centigrade or less for frozen products.

All packaging should be original and not tampered with or forged. This would indicate that the product is not the original contents and has been produced by a fraudulent company. Do not buy these products under any circumstances because they threaten your health.

All reputable retail businesses that sell food should display up to date licences from all the required regulatory authorities as required by law. Check with your local authority to find out what licences a food shop or a supermarket must have to be open for business in your area.

Rule No.2)

Prevent bacteria from entering your food

Ok! This is the pace to tell you a little about bacteria and how they multiply.

All bacteria, when they have the right conditions begin to multiply. The conditions that they need are,

a) a temperature of above 10 degrees centigrade, (some say 5 degrees).

b) A food source. Bacteria break down all organic matter into sugars and use the basic food molecule which is mono- saccharide glucose for their metabolism.

Bacteria need only 20 minutes to adjust themselves to a new food source. For example, Supposing a bacteria was on a sugary food and suddenly found itself on fish, the transition the bacteria would need to be able to digest the new food source is twenty minutes.

c) A source of water.

On acquiring suitable conditions bacteria then commense to reproduce at a rate of one division of the whole colony every 20 minutes. E.G. If you had 1000 bacteria on a piece of food to begin with, you will have one million bacteria after 20 minutes. In the following 20 minutes the number would jump up to one million million bacteria. After that the numbers are simply astronomical!

Keeping bacteria from getting into your food is primarily down to prevention of cross contamination.

Cross contamination means the contact of any food source with any form of contamination from another source. This could be other food (raw or processed), Packaging, garbage, contaminated water or air, unclean or sick humans, animal life, or unclean tools and surfaces.

In good professional kitchens there are different fridges for different functions. For example, there is one fridge for dairy, another for cold fresh vegetables and another for food that has been cooked.

As home owners we do not usually have this luxury therefore it is advised to keep cooked foods at the top of the fridge and raw materials at the bottom in closed containers. This way the risk of contamination is greatly lessened.

Eggs, especially, should be kept in a closed container because they have many bacteria on their outer shells.

Remember to wash your hands and arms to the elbow before preparing food. Cut your salads first and then go onto the foods that are to be cooked making sure to thoroughly wash your board before moving on to different types of food.

Wash all surfaces before and after work with a good detergent. Put cloths into the wash after each usage. Always start with a clean cloth.