Zero-tolerance, pesticides

The only apprehension of prospective industrial radiation processors with the nonmeasurability criterion comes from the analogies with the history of pesticide residues in foods U). Pesticides are cleared on the basis of either zero tolerance or finite tolerance, and use is rated as safe for a zero-tolerance pesticide when the residue on foods cannot be measured. However, improvements in measurement techniques with time have changed the definition of zero tolerance, sometimes abruptly. Radiation processors are apprehensive of similar experiences with radioactivity induced in food. 

A unified safety standard for raw and processed foods This amends the Delaney clause in the FFDCA. Under the Delaney clause, a chemical that causes cancer in experimental animals (regardless of dose) shall not be allowed in processed food. Under the FQPA, pesticide residues shown to cause cancer in humans or animals are allowed on food if the EPA determines that the tolerance is safe, meaning that there is a reasonable certainty that no harm will result from exposure to the pesticide. This amendment is necessary mainly because of improved analytical capabilities. Under the Delaney clause, a carcinogen pesticide would be given a zero tolerance in processed food. However, zero tolerance caused many problems. As the analytical sensitivity increased, concentrations that were zero by old methods became measurable. A unified safety standard eliminates longstanding problems posed by multiple standards for pesticides in raw and processed foods. 

The zero tolerance approach for pesticides in drinking water... 

A completely different approach is followed by the EU for the management of xenobiotics in drinking water and, in particular, of pesticides. The EU has applied a policy of zero tolerance toward the presence of pesticides in drinking water since 1980. At that time it adopted a policy establishing the maximum acceptable level of pesticides in drinking water at the concentration of 0.1 (xg/1 in Directive 80/778/EEC (EEC Council Directive, 1980). This is taken as a practically zero level of tolerance, considering the analytical detection limit for most pesticides at the time of promulgation of the Directive. 

Internationally recognized food standards, i.e.. Codex standards, have been established for more than three decades as standards for facilitating international trade and solving trade disputes. One of the many standards established by Codex is the maximum residue limit (MRLs) for pesticides on food commodities in international trade. Codex MRLs are used as national standards by many countries however, some countries continue to establish their own MRLs or tolerances and impose zero tolerance to residues of pesticides on imported crops which do not have nationally/regionally agreed-upon MRLs. Therefore, the acceptance of Codex MRLs among countries is different. An example of the variation in MRLs for carbaryl in some commodities is shown in Table 1. 

Most of the current efforts to amend FIFRA concentrate on the tolerance and food safety provisions of FIFRA and the FFDCA. For years the EPA has interpreted the Delaney Clause of the FFDCA to impose a negligible risk standard for pesticide residues on food, whereas others, including influential environmental groups, read the section to allow zero risk. EPA s interpretation was struck down by the Ninth Circuit in Les v. Reilly. The EPA asked the Supreme Court to review that decision. Their petition was denied on March 8, 1993. Legislation has been proposed on several occasions to change the outcome of Les v. Reilly however, none to date has been adopted... 

Over 90% of the violations reported in the EWG study involve two kinds of illegal pesticides no-tolerance violations, where the pesticide is found on a crop even though the allowable level for the pesticide on that crop is zero and overtolerance violations, where the amount of the pesticide found exceeds the legal limit (or tolerance) for tliat crop. 

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