Avocados – Fewer than 1% of avocados tested positive for pesticides. Best of all, only one pesticide of any kind was found on all the avocados tested. For these reasons, the Environmental Working Group ranked avocados as the No. 1 cleanest produce.
Sweet corn – Less than 2% of sweet corn, the second-cleanest produce, showed detectable levels of pesticides. Because a small portion of corn is grown from genetically modified seeds, the group suggests that those who wish to avoid genetically altered foods buy organic corn.
Pineapples – Nearly all the pineapples tested -- 90% -- showed no residual pesticides, while just five pesticides could be detected on any of the samples. For these reasons, pineapples fill position three on the clean list.
Cabbage – Overall, 86% of cabbage samples contained no detectable pesticides. Additionally, just two of more than 700 samples tested contained more than one pesticide. For these reasons, cabbage ranked fourth on the list of cleanest produce.
Onions – Fifth-placed onions contained three or fewer pesticides overall, while fewer than one in 10 contained any pesticides.