Humans can get exposed to various chemical substances via oral route (i.e, eating food, drinking groundwater, hand to mouth transfer). It is necessary to determine the maximum amount of a chemical that can be ingested on a daily basis to protect human health. That is why we need to calculate the Acceptable Daily Intake (ADI). For pesticide residues and food contaminants, ADI may also be called Tolerable Daily Intake (TDI).
ADIs serve to protect the health of consumers and to make international trade in food easier. The ADI is a practical approach to determining the safety of food additives and is a means of achieving some harmonisation of regulatory control. The advantage of regulatory and advisory bodies setting ADIs for food additives is that they are universally applicable in different countries and to all sectors of the population.