Contamination of food with extremely low levels of certain compounds can cause an unpleasant taste. This can result in the destruction of vast stocks of product, and very substantial financial losses to food companies. The concentration of the alien compound in the food can be so low that very sophisticated equipment is needed to identify the components and to determine its source. It is vital that every company involved in the production, distribution and sale of foodstuffs are fully aware of the ways in which contamination can accrue, how it can be avoided, and what steps need to be taken...