Acceptable Daily Intake
The Acceptable Daily Intake, or ADI, is defined as an estimate of the amount of a food additive, expressed on a body weight basis, that can be ingested daily over a lifetime without appreciable health risk. It is measured in milligrams per kilogram of body weight.
The concept of the ADI was initially developed by the Joint FAO/WHO Expert Committee on Food Additives, or JEFCA. It was later endorsed by the Scientific Committee on Food, and its successor, the European Food Safety Authority (EFSA).
How is the ADI for an additive determined?
It is usually derived from long-term animal feeding studies. First, the No Adverse Effect Level is determined, which is the highest dose of an additive that can be fed to the most sensitive animal species on a daily basis with no toxic effects. A large safety factor is then added – usually by dividing the level in animals by 100 – to arrive at a safe level for humans. For example, if the no effect level in animals is found to be 100mg/kg, then the human ADI would be set at 1mg/kg.
The safety factor is built in partly to account for the differences between animals and humans, and also to allow for the variability between different people, such as age, health and how well nourished they are.
The ADI is not a level of toxicity – it is a level that has been found to be safe. Consuming more than this on occasions is unlikely to cause health problems, as long as the average daily intake is below the ADI. It should always be compared with average consumption levels over long periods, not with intakes on a day-to-day basis.
ADI has been proved to be the best practical tool available for legislators. It has contributed to a uniform approach around the world to express the safety of a substance in relation to human consumption levels of additives.
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