Food safety

Guidance on setting of acute reference dose (ARfD) for pesticides

The need to consider acute effects of pesticide residue intake has been acknowledged for many years, and the concept of the Acute Reference Dose (ARfD) was developed by the Joint FAO/WHO Meeting on Pesticide Residues (JMPR) in 1994. Since then, there has been a progressive increase in the establishment of ARfDs for particular pesticides to address potential exposure to residues in food and drinking water at relatively higher doses for short-term periods, due to accidental or incidental events. JMPR has continuously updated its procedure on the setting of ARfDs.

The ARfD is defined as "an estimate of the amount a substance in food or drinking water, normally expressed on a body weight basis, that can be ingested in a period of 24 h or less without appreciable health risks to the consumer on the basis of all known facts at the time of the evaluation" (JMPR, 2002).

Internationally-acceptable, science-based ARfDs require a systematic, step-wise process leading to increased transparency and standardization. An international group of experts, linked to the Joint Meeting on Pesticide Residues (JMPR), has recently developed Guidance on the setting of acute reference dose (ARfD) for pesticides, which was published as a scientific publication in a peer-reviewed journal. The new WHO Guidance on the setting of ARfDs builds upon existing guidance developed by JMPR and by national regulatory authorities, and provides a comprehensive guide on the process of selecting and evaluating appropriate toxicological endpoints for acute guidance values. The Guidance presents a step-wise approach on the derivation of ARfDs and provides specific guidance on relevant toxicological endpoints, namely haematotoxicity, immunotoxicity, neurotoxicity, liver and kidney toxicity, endocrine effects and developmental effects.

The Guidance has been published in the journal Food and Chemical Toxicology: R. Solecki, L. Davies, V. Dellarco, I. Dewhurst, M. van Raaij and A. Tritscher. Guidance on setting of acute reference dose (ARfD) for pesticides. Food and Chemical Toxicology, 43, 1569-1593 (2005).

This report can be considered as the most authoritative, up-to-date procedural guidance available and should help to provide the basis for international harmonization in ARfD methodology.