Acceptable daily intake

The acceptable daily intake, or ADI, is the amount of a substance a person can consume every day across a whole lifetime without appreciable risk to health. It is expressed per kilogram of body weight per day, so the figure scales with the person. A 60 kg adult and a 20 kg child do not share one absolute limit. The number is derived, not measured. Toxicologists identify the no observed adverse effect level, or NOAEL: the highest dose in animal studies that produced no adverse effect. That dose is then divided by a safety factor, conventionally 100. The factor splits into two tenfold steps, one for differences between species and one for differences between individual humans. Where the data are thin or a study was short, evaluators may apply a larger factor. ADIs are set by the European Food Safety Authority (EFSA), the Joint FAO/WHO Expert Committee on Food Additives (JECFA), and the US Food and Drug Administration (FDA), among others. Their figures can differ for the same additive because they weigh the same studies differently. Two things are widely misread. An ADI is a long-run average, not a daily ceiling, so exceeding it once is not a poisoning event. And some substances carry no numerical ADI at all, marked 'not specified', which signals low concern rather than an oversight.

Last reviewed: August 25, 2026

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