Food safety has become one of the major worries for mankind.This worry has three major sources: the chemical contamination of agricultural products, the use of additives, preservatives and colourings in  a large number of food products  and the consumption of  ready-made food.Perhaps the first cause for worry about food safety is the highly intensive mode of farming and agribusiness now prevailing in industrialised countries.This has led big companies to use chemicals, fertilisers and pesticides to ensure maximum output.Consumer requirements have led manufacturers to introduce colourings, additives and preservatives.Scientists maintain that some colourings and sugar substitutes can cause cancer, diabetes and other metabolic disorders.As a result, fruits and vegetables are contaminated by chemicals which may prove harmful to our health.Some of them have been suspected of being dangerous while others have definitely been classified as harmful by independent research laboratories.