Provisional maximum tolerated daily intake

For contaminants and naturally occurring toxicants, levels corresponding to tolerable intakes such as the provisional maximum tolerable daily intake (PMTDI) or provisional tolerable weekly intake (PTWI) are established when there is an identifiable no-observed-effect level, that is, a threshold of effect can be assumed based on available data. When a noobserved-effect level cannot be identified, the Committee provides other advice, such as identification of the food(s) that contributes most to intake. This allows for targeted management actions in order to decrease exposure. 

MTDI = maximum tolerable daily intake, or provisional maximum tolerable daily intake (PMTDI) a term used for description of the end point of contaminants with no cumulative properties. Its value represents permissible human exposure as a result of the natural occurrence of the substance in food or drinking water. In the case of trace elements that are both essential nutrients and unavoidable constituents of food, a range is expressed, the lower value representing the level of essentiality and the upper value the PMTDI. 

Overexposure to zinc by food, water, and air commonly poses no risk to the general population. Long-term administration of zinc (100-150 mg per day) to patients to promote wound healing is usually well tolerated, but anemia may be induced in case of low copper status. This effect is readily reversible, however. Using a safety factor of 10 this means that an additional zinc intake of 10-15 mg per day does not constitute a health hazard (US ERA 1980). The provisional maximum tolerable daily intake for man has been estimated at 0.3 to 1.0 mg Znkg body weight (WHO 1983). 

PMTDI (Provisional Maximum Tolerable Daily Intake) A provisional estimate of the amount of a hazardous substance with no cumulative properties in food or drinking water, expressed on a body-weight basis, that can be ingested daily over a lifetime without appreciable health risk. 

PTWI, Provisionably tolerable weekly intake PMTDI, Provisionably maximum tolerable daily intake PDDR, Provisionably daily dietary requirement. 

PMTDI Provisional Maximum Tolerable Daily Intake... 

PMTDI provisional maximum tolerable daily intake... 

Chloropropanols show various toxic effects. 3-CPD causes infertility in rats and suppression of the immune function and was shown to be genotoxic in several in vitro assays, but is not genotoxic and mutagenic in vivo. It was classified by the lARC as a chemical of the 2B group, and probably carcinogenic to humans. In 2001, the Scientific Committee on Food (SCF) established a tolerable daily intake (TDI) for 3-CPD at 2 p-g/kg body weight, and in 2002 the Joint FAO/WHO Expert Committee on Food Additives (JECFA) estabUshed a provisional maximal tolerable daily intake for 3-CPD, similarly at 2 Hg/kg body weight In the EU, maximum levels of... 

The World Health Organization (WHO) has set a provisional tolerable weekly intake level for OTA at lOOng/Kg of body weight, taking its potentially carcinogenic effect into account (JEFCA, 2001). The tolerated maximum concentrations are based on a tolerable daily intake of 5 ng/(kg of body weight) suggested by the ED Scientific Committee on Food (Commission of the European Communities, 1998). CE... 

Abbreviations EPA, Environmental Protection Agency ATSDR, Agency for Toxic Substances and Disease Registry FDA Food and Drug Administration NOAEL no-observed-adverse-effect level LOAEL, lowest-observed-adverse-effect level UF, uncertainty factor SF, safety factor RfD, reference dose (an amount of a substance that is anticipated to be without adverse health effects in humans, including sensitive populations, when ingested daily over a lifetime MRL, minimal risk level (an estimate of daily human exposure to a hazardous substance that is likely to be without an appreciable risk of adverse noncancer health effects over a specified route and duration of exposure) pTDI, provisional tolerable daily intake (maximum daily exposure level to a contaminant provisional meaning that it is considered temporary until more data are available, especially the completed Seychelles study) JECFA, Joint FAO/WHO Expert Conunittee on Food Additives pTWl, provisional tolerable weekly intake. 

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