No Observed Adverse Effect Level (NOAEL)
The greatest concentration or amount of a substance at which no detectable adverse effects occur in an exposed population
In food safety, the No Observed Adverse Effect Level (NOAEL) is the highest amount of a substance that can be consumed or absorbed without causing any harmful effects. It is derived from experimental studies, most often animal studies, by observing how different doses of a substance affect health. It represents a level at which no negative health effects are seen.
EFSA uses the NOAEL as a key starting point in risk assessment. It applies safety factors to the NOAEL to account for differences between animals and humans and for variability among people. This process helps EFSA set safe intake levels, such as Acceptable Daily Intakes (ADIs) or Tolerable Daily Intakes (TDIs), which are then used to ensure that exposure to substances in food remains safe for consumers.