Tolerable daily intake (TDI) refers to the daily amount of a chemical that has been assessed safe for human being on long-term basis (usually whole lifetime). Originally

acceptable daily intake Acceptable daily intake or ADI is a measure of the amount of a specific substance (originally applied for a food additive, later also for a residue of a veterinary drug or pesticide) in food or drinking water that can be ingested (orally) daily ove ...

(ADI) was introduced in 1961 to define the daily intake of a

food additive Food additives are substances added to food to preserve flavor or enhance taste, appearance, or other sensory qualities. Some additives have been used for centuries as part of an effort to preserve food, for example vinegar (pickling), salt (sal ...

which, during the entire lifetime, appears to be without appreciable

risk In simple terms, risk is the possibility of something bad happening. Risk involves uncertainty about the effects/implications of an activity with respect to something that humans value (such as health, well-being, wealth, property or the environme ...

. For contaminants and other foreign chemicals not used intentionally, the term TDI is often preferred. Both ADI and TDI are usually assessed based on animal experiments, and it is most often hundreds of times lower than the dose causing no observable adverse effect (NOAEL) in the most sensitive tested animal species. Because the confounding factors (safety factors) may vary depending on the quality of data and the type of

adverse effect An adverse effect is an undesired harmful effect resulting from a Pharmaceutical drug, medication or other Surgery#Definitions, intervention, such as surgery. An adverse effect may be termed a "side effect", when judged to be secondary to a main ...

, TDI values are not good estimates of the harmfulness of chemicals, and must be considered administrative tools to set allowable limits for chemicals, rather than scientific measures. The threshold limit value (TLV) of a chemical substance is a level to which it is believed a worker can be exposed day after day for a working lifetime without adverse effects.

References

{{Reflist Toxicology fr:dose journalière tolérable zh:每日耐受量 ja:耐容一日摂取量