The EWG Guide to Pesticides in produce is an exhaustive study that ranks pesticide contamination in fruits and vegetables. It is created with the purpose of informing the public of the amount of pesticides being used in the production of vegetables and fruits they consume.

The samples to be tested are taken by the U.S. Department of Agriculture and the federal Food and Drug Administration. The most recent version of the guide includes samplings from 2014 since foods are not tested every year. The guide might even include data from 2009. 

When comparing foods, EWG focuses on six measures of pesticide contamination:

  • Percent of samples tested with detectable pesticides
  • Percent of samples with two or more detectable pesticides
  • Average number of pesticides found on a single sample
  • Average amount of pesticides found, measured in parts per million
  • Maximum number of pesticides found on a single sample
  • Total number of pesticides found on the commodity

When using the guide, consumers can make better decisions by choosing food with fewer levels of pesticides. Consumers usually find that foods they want to eat have higher concentration of pesticides than they can tolerate. In this case, it is suggested they make an effort to look for the organic versions of these foods.

The samples tested and found to be high in pesticides make it to the Dirty Dozen™ list.  This year, these foods include:  strawberries, apples, nectarines, peaches, celery, grapes, cherries, spinach, tomatoes, sweet bell peppers, cherry tomatoes, and cucumbers.  They were the ones that showed the largest amount of pesticides.

On the other hand, the guide also singles out those foods with the lowest pesticide content. This is the Clean Fifteen™ list.  These foods are less likely to have pesticide residues. They are avocados, sweet corn, pineapples, cabbage, frozen sweet peas, onions, asparagus, mangoes, papayas, kiwis, eggplant, honeydew melon, grapefruit, cantaloupe, and cauliflower.