TDIs are determined through rigorous toxicological studies and assessments. The process typically involves identifying the No-Observed-Adverse-Effect Level (NOAEL) from animal studies. This is the highest dose at which no adverse effects are observed. The NOAEL is then divided by a series of safety factors to account for uncertainties, such as differences in sensitivity between humans and test animals, and variability among humans themselves. These factors ensure that the TDI is protective of all populations, including vulnerable groups like children and pregnant women.
