Acceptable Limits for Pesticides in Foods: The FAO/WHO Approach

Abstract

Pesticides have made great contributions to increases in yield and in quality of agricultural produce during recent years. Potential risks to manufacturers, to farmers, to wild-life, to the general environment and to consumers of foods are now well recognised. In spite of increased emphasis, the use of pesticides is increasing. This pattern seems likely to continue.

In most countries there are inter-related powers to control both the introduction of new pesticides and the presence of residues in foods on the market. The residue control usually takes the form of levels which may not be exceeded in specified foods. Many countries brought in such residue laws during the late 1950s and early 1960s. The adoption of different levels of acceptance in different countries caused problems in international commerce: some countries also lacked the specialists needed for deciding on appropriate levels. Member governments therefore sought guidance from the FAO and the WHO. A joint meeting of experts was called in 1961. It advised that the approach should be to assemble and evaluate data on the toxicology and occurrence of residues and to base recommendations on the findings.

The present paper outlines the processes by which the Joint FAO/WHO Meeting of independent experts evaluates data, draws conclusions and makes recommendations for acceptable residue levels, these being subsequently considered for adoption by governments through the procedures of the Codex Alimentarius Commission.

The kinds of data required to evaluate toxicology and establish Acceptable Daily Intakes are outlined, as also is the use of this parameter in making recommendations for maximum acceptable residue limits: the latter figures are initially derived from a study of residues detected after following officially recommended practices. The paper concludes with a discussion on the value and overall impacts of the activity.