Tolerable daily intake (TDI) refers to the daily amount of a chemical contaminant that has been assessed safe for human exposure on long-term basis (usually whole lifetime).
TDI specifically occurs to chemicals that humans are exposed to unintentionally or as a contaminant,
where
acceptable daily intake refers to chemicals that are intentional added.
TDI is generally written as a value of exposure (e.g. in milligrams) per kilogram (kg) body weight. 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 medication or other intervention, such as surgery. An adverse effect may be termed a "side effect", when judged to be secondary to a main or therapeutic effect. The term compli ...
, 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.
Examples of Tolerable Daily Intake
World Health Organization
The World Health Organization (WHO) has introduced a TDI for melamine as 0.2 milligrams (mg)/kg body weight (b.w.) as of 2008. Similarly the established TDI range for dioxins according to WHO is 1-4 picograms toxic equivalency/kg body weight as of 1998. WHO's provisional maximum tolerable daily intake for all sources of iodine
Iodine is a chemical element; it has symbol I and atomic number 53. The heaviest of the stable halogens, it exists at standard conditions as a semi-lustrous, non-metallic solid that melts to form a deep violet liquid at , and boils to a vi ...
combined is 0.017 mg/kg b.w.
North America
Canada
The Canadian Government Health Protection Branch also uses tolerable daily intake.
United States
The United States
The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...
Food and Drug Administration
The United States Food and Drug Administration (FDA or US FDA) is a List of United States federal agencies, federal agency of the United States Department of Health and Human Services, Department of Health and Human Services. The FDA is respo ...
has used TDI for substances such as melamine, which is currently set at 0.063 mg/kg b.w./day.
Europe
European Food Safety Authority
The European Food Safety Authority
The European Food Safety Authority (EFSA) is the agency of the European Union (EU) that provides independent scientific advice and communicates on existing and emerging risks associated with the food chain. EFSA was established in February 2002 ...
has set a TDI for Bisphenol A
Bisphenol A (BPA) is a chemical compound primarily used in the manufacturing of various plastics. It is a colourless solid which is Solubility, soluble in most common organic solvents, but has very poor solubility in water. BPA is produced on a ...
at 0.2 nanograms per kilogram of b.w./day as of 2023.
Asia
Taiwan
As of 2011, the Taiwan Food and Drug Administration follows the TDI values set by the European Food Safety Administrations.
Korea
The Official Journal of Korean Society of Toxicology as requested by the Korean National Institute for Food and Drug Safety Evaluation has recommend a TDI for BPA to be set at 0.05 mg/kg b.w./day.
See also
Recommended daily allowance
Tolerable weekly intake
Acceptable daily intake
References
{{Reflist
Toxicology
fr:Dose journalière tolérable
ja:耐容一日摂取量
zh:每日耐受量