Each year the Environmental Working Group, an environmental organization based in the United States, publishes a list they call the “Dirty Dozen”. These are the fruits and vegetables that when conventionally grown using chemical pesticides and fertilizers carry the highest residues. If organically grown isn’t an option for you, simply avoid these fruits and vegetables altogether. The list is updated each year, but here is the most recent list (2014).
Similarly, the Environmental Working Group publishes a list of “The Clean 15” fruits and vegetables that even when conventionally grown contain very low levels of chemical pesticides or fertilizer residue. These items are acceptable to purchase conventionally grown.
You might want to snap a photo of these two lists and keep them on your phone to reference while shopping. Or you can download the Environmental Working Group’s app to your phone or tablet.