Pesticide tolerances

EPA. 2001. Methyl parathion notice of pesticide tolerance revocations final rule. Department of Health and Human Services. U.S. Environmental Protection Agency. 40 CFR Part 180. Federal Register 66(4) 1242-1246. 

Pesticide Tolerances in Food-endouslfan and endosulfan sulfate residue in or on dried tea... 

The records required for field residue study authentication are the same records that would be required to reconstruct the study. Although this total volume of information is a necessary part of the GLP study record, the field summary report is a small fraction of that record. The field summary report is simply the information the EPA reviewers wish to see as they consider the data and determine how well they represent the crop situation for which the pesticide tolerance is being requested. At the current time, the field summary report should contain the information requested on pp. 48 and 49 of OPPTS 860.1500. The summary report for each test site in a study will typically form an appendix in the final study report. This information must be accurately extracted from the raw data notebook or field record and must be audited by... 

The FFDCA governs the establishment of pesticide tolerance for food and feed products. A tolerance is the maximum level of pesticide residues allowed in or on human food and animal feed. ... 

Assure that pesticide tolerances are safe for vulnerable populations, in particular, infants, children and the elderly, based on a reasonable certainty of no harm health-based standard, instead of the previous cost-benefit balancing standard ... 

The EPA was also directed to review the 9721 tolerances on the books in 1996 to assure that they were in compliance with the FQPA s new safety standard. The agency was responsible for reviewing the riskiest one-third of pesticide tolerances within three years of passage (i.e. by summer 1999). Two-thirds of existing tolerances were to be reviewed and brought into compliance with the new statute six years after passage (summer 2002). Within 10 years, all tolerances were to be reviewed and adjusted as needed, or by August 2006. 

U.S. Environmental Protection Agency (USEPA), pesticide tolerance levels and, 14 337... 

Weed Science Society of America. (1994). Herbicide handbook. Champaign, IL Weed Science Society of America. United States Environmental Protection Agency. (1997). Glyphosate Pesticide tolerances Federal Register April 11,1997 (Volume 62, Number 70). 

The processes that the EPA applies to establish pesticide tolerances are confusing and are frequently misunderstood. Readers interested in EPA s tolerance-setting practices should consider reading a comprehensive paper on the subject (Winter, 1992), however the following text gives a brief summary. 

Pesticide residues will be considered illegal when pesticides are detected at levels that exceed the tolerance level, or when residues of a pesticide are detected, at any level, on a commodity for which a tolerance has not been established. Illegal residues should not be confused with unsafe residues, however, since pesticide tolerances are most appropriately viewed as enforcement tools rather than as safety standards. 

It is critical to realize that pesticide tolerances themselves are not safety standards but rather enforcement tools for indicating whether pesticides have been applied according to directions. Violative residues result when residue levels exceed the tolerance due to the misapplication of a pesticide, or when residues at any level are found on a commodity for which a tolerance was not established (which could result from product misuse). While a few isolated cases of violative residues have resulted in human harm, the vast majority of violative residues are of little or no toxicological consequence. 

Winter, C.K. (1992). Pesticide tolerances and their relevance as safety standards, Reg. 

The FDA is responsible for enforcing the EPA-established pesticide tolerances for foods shipped interstate, with the exception of meat and poultry, which are the responsibility of the USDA (30). 

Federal and state regulatory monitoring programs that enforce pesticide tolerances provide a direct mechanism to manage pesticides in foods. In cases where violative residues are detected, the foods on which the residues are... 

At the present time, most US pesticide tolerances were established prior to the passage of FQPA. In assessing consumer risk from exposure to pesticides, the EPA first estimates consumer exposure. The maximum legal exposure to the pesticide is usually first calculated by assuming that... 

It should be recognized that US pesticide tolerances established by the aforementioned process, in combination with regulatory monitoring programs, serve important roles as enforcement tools that provide economic disincentives for pesticide users to misuse pesticides. At the same time, the tolerances should not be considered as safety standards since violative residues rarely represent residues of toxicological concern (Winter, 1992a). 

In addition to the need for scientific improvements to allow probabilistic risk assessments to be properly performed and interpreted, there also exists a need to educate stakeholders about what the US system for tolerance establishment and monitoring does and does not do. In simplest terms, the US system can be described as a food quality system but not necessarily a food safety system. This results from the fact that the pesticide tolerances are not safety standards but rather exist as enforcement tools that allow an assessment of how well pesticide application regulations are adhered to. Violative residues demonstrate the likelihood of pesticide misuse but should not be considered, in the vast majority of cases, to represent unsafe residues. Safety considerations govern whether or not the use of pesticides on specified commodities will be permitted tolerances, when granted, serve as indicators of good agricultural practices rather than as toxicological benchmarks. 

U.S. Environmental Protection Agency, Pesticide tolerance for 0,0-dimethyl S-[(4-OXO-l,2,3-benzotriazin-3(4H)-YL)methyl] phosphorodithioate (azinphos-methyl). Fed. Reg. 54 46082-84, 1989. 

The Federal Food, Drug, and Cosmetic Act (FFDCA) deals mainly with pesticide tolerance. Pesticide tolerances are set by the EPA and enforced by the FDA or, in the case of meat, milk, poultry, and eggs, by USDA agencies. 

A pesticide tolerance is the maximum amount of a pesticide residue that can be present on food. The tolerance is expressed in ppm, or parts of the pesticide per million parts of rood by weight. A chemical generally regarded as safe need not be given a tolerance, or the chemical may be exempted from the requirement for a tolerance. This might occur when the chemical is used on nonbearing fruit trees, for example. For toxic chemicals, unified standards need to be set for raw and processed foods. 

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. 

FOOD STANDARDS, PESTICIDE TOLERANCES, ADDITIVES, AND IMPURITIES ... 

The ADI or RfD is the measure of the hazard the chemical has for humans. It is that level of chemical that is deemed to be safe for daily lifetime human consumption. For safe residue levels to be set, exposure must now be determined. Every regulatory agency also has a method to accomplish this. The problem is determining how much food a person must eat to achieve this ADI. There have been numerous studies that have assessed the patterns of our food consumption to get at what is an average diet in our country. In cases such as milk, where the food may comprise the infant s entire diet, consumption is often overestimated. The presentation of these numbers is beyond the scope of this appendix since my purpose is only to illustrate the process that determines a pesticide tolerance in the field that is the trip wire for concern. This number is the concentration on the product itself, which based on patterns of food consumption, will determine the amount of daily consumption of the chemical. 

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