Theoretical maximum daily intake

Although the main basis for proposing MRLs is the data from supervised trials, when considering the proposals Member States calculate the theoretical maximum daily intake that could occur if the proposed MRLs were adopted,... 

When calculating chronic dietary exposure, the deterministic models use point values for both food consumption and residue concentration, thereby yielding a point estimate of dietary exposure. In the US, the initial chronic dietary exposure estimate is the Theoretical Maximum Residue Contribution (TMRC) and is analogous to the Theoretical Maximum Daily Intake (TMDI) used to estimate chronic dietary exposure in the EU. Both the TMRC and the TMDI are relatively conservative estimates of dietary expostire. The TMRC is calculated as the product of the mean consumption value and the US pesticide tolerance [6]. In the EU, the TMDI is calculated as the product of the mean consumption value and the Maximum Residue Limit (MRL) [7]. The objective of both calculations is essentially identical to calculate an estimate of the central tendency of the dietary exposure. Both calculated values use the central tendency dietary exposure estimate as the estimate of chronic (long-term) dietary exposure and calculate it using mean consumption data and the maximum residue permitted on the commodity. 

The daily dietary intakes of BHA and BHT have been estimated in many countries. The daily intakes of BHA and BHT in Japan in 1998 were 0.119 and 0.109 mg/d/person, which reflect 0.5% and 0.7% of the acceptable daily intake (ADI), respectively (35). The estimates of theoretical maximum daily intake (TMDl) of BHA and BHT in Brazil published in 2001 were in the range of... 

Threshold limit value (ACGIEI) Theoretical maximum daily intake Time-weighted average Time-weighted average concentration... 

On the basis of the food basket, the EU authority (EMA/CVMP) then requires applicants for MAs to estimate the theoretical maximum daily intake (TMDI) for persons weighing 60 kg, applying the equation ... 

TMDI (Theoretical Maximum Daily Intake) will be calculated as follows TMDI=X[MRLiXFJ... 

Leclercq, C., Arcella, D., and Turrini, A. Estimates of the theoretical maximum daily intake of erythorhic acid, gaUates, butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) in Italy A stepwise approach. Food Chem. Toxicol. 38,1075, 2000. 

LAMBE J., CADBEY P., GIBNEY M., (2002), Comparison of stochastic modelling of the intakes of intentionally added flavouring substances with theoretical added maximum daily intakes (TAMDI) and maximised survey-derived daily intakes (MSDI), Food Additives and Contaminants, 19, pp 2-14. 

This maximum legal exposure, often referred to as the Theoretical Maximum Residue Contribution, or TMRC, is compared with established toxicological criteria such as the reference dose (RfD) or Acceptable Daily Intake (ADI) which represent, after analysis of animal toxicology data and extrapolations to humans, the daily exposure that is not considered to present any appreciable level of risk. When it is determined that the TMRC exposure is below the RfD or ADI, the EPA usually considers the risks from the pesticide in question to be negligible and approves the manufacturer s petition to establish a tolerance at or slightly greater than the maximum levels identified from the manufacturer s controlled field trials (Winter, 1992a). 

The previous assumptions can be used to calculate maximum theoretical daily intake of levamisole equivalents if a consumer ate the standard meat diet containing concentrations of levamisole at the proposed MRLs. The maximum ingested residue of the parent drug and its equivalents is 397pgday, which consists of 14pgday of parent drug and 383pgday of levamisole equivalents. The calculation is shown in Table 1. 

To determine the possible exposure level via the food, the "theoretical daily intake" (TDl) was calculated. This figure was derived by utilizing data on the rate of disappearance of the food item in Canada, provided by Statistics Canada, and determining from these data, the consumption of the crop per capita (assuming disappearance rate and consumption to be comparable). It was assumed that the total crop could have residues present at about the level of analytical sensitivity of the method of detection. Thus based on the consumption level and the maximum residue level, an estimate of exposure from each crop can be calculated. The total exposure from all crops is the TDI. 

No allowable daily intake of atrazine in the human diet has been established, although 0.0375 mg/kg BW daily has been proposed -equivalent to 2.25 mg daily for a 60-kg adult, or 1.5 mg/kg diet, based on 1.5 kg food daily. In humans, the theoretical maximum residue contribution (TRMC) - a worst case estimate of dietary exposure - is 0.77 mg daily, assuming 1.5 kg of food eaten daily this is equivalent to 0.51 mg/kg diet, or 0.013 mg/kg BW daily for a 60-kg person. Another TRMC calculation is based on 0.233 mg daily per 1.5 kg diet, equivalent to 0.156 mg/kg diet, or 0.0039 mg/kg... 

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