[Methods for assessing permissible levels of intentional and unintentional food additives (author's transl)].

Foods may contain intentional and unintentional additives. The former group includes, for example, flavours, colouring substances and preservatives, while the latter includes pesticides and mycotoxins. To determine the amount of these substances that are admissible in man, extensive toxicological tests have to be performed with experimental animals to establish a no toxic effect level. Based on the no toxic effect level and applying a safety factor an "acceptable daily intake" (ADI) can be calculated for human beings. The problems outlined in the article are illustrated by several examples, such as the presence of DDT and aflatoxin M1 in milk and of mercury in fish.