Project Details:

Regulatory limits for pesticide residues in water

To examine the various methodologies for setting standards for permissible levels of pesticide residues in waters and to recommend suitable methodologies and data requirements.

Remarks: Extension of Project640/41/97 ; Proposed cooperative project with Commission on Soiland Water (VI.3)

Setting standards for pesticide residues in waters is complex. First we must decide which type of water is relevant to the proposed standard, e.g. drinking water, reservoir water, lakes and streams, ground water, water for aquaculture, irrigation water and drinking water for farm animals. Second, should we adopt a risk assessment based approach or a "no more than reasonable if good practices are followed" approach, or a combination of the two? Different approaches will lead to different maximum limits being set. A standard based on a risk to human health or the environment may allow much higher levels of residue in the water than would ever occur in practice. An arbitrarily chosen maximum limit may be economically wasteful in requiring correction of harmless residues that do not meet the standard while ignoring more hazardous contaminants that are technically not pesticides.

Project completed - IUPAC Technical Report published in Pure Appl. Chem. 75(8), 1123-1155, 2003.

• Hamilton, Denis