Food and drinking water are major sources of human exposure to a large number of chemicals added intentionally for technological reasons or present unintentionally due to contamination. On the other hand, there is a public demand for an essentially risk-free supply of food and drinking water. The concern over the presence of chemicals in the human diet received further emphasis through the development of toxicological and analytical methodology with increased sensitivity over the years. In order to minimize the potential health hazards to the consumers, standards have been established which indicate levels of consumption that are - according to scientific evidence - considered safe and which, consequently, permit control measures to be taken. In this context, public perception of a particular risk, may not always be in line with what might be considered a 'real' risk. Thus, while in the public opinion risk associated with smoking or over-nutrition might be accepted or underestimated, certain food chemical related risks may not be accepted and are sometimes perceived as alarmingly high.