The EWG bases its rankings on data from the U.S. Department of Agriculture and the Food and Drug Administration. The produce is tested for pesticide residues and ranked based on the number of different pesticides detected, the concentration of residues, and the frequency of detection. While the guide is a useful tool, itâs important to understand in Toxicology that not all pesticides are equally harmful, and their risk often depends on the level and duration of exposure.
