The FDA and USDA test a handful* of foods for pesticide residues every year. They won’t test for glyphosate/Roundup, though, the chemical that the International Agency for Research on Cancer (IARC) just said was “probably carcinogenic to humans”:
Both FDA and USDA fail to test for glyphosate, the active ingredient in Roundup, one of the most widely used herbicides in the world.
According to a USDA spokesman, test measures required for glyphosate are “extremely expensive…to do on a regular basis.”
– USDA Reports Pesticide Residues on Over Half of Food Tested
Recall that Monsanto requested from EPA (and subsequently received) approval for higher tolerance levels for glyphosate/Roundup. So, even if USDA or FDA do start testing, they will be able to say the pesticide residue levels are below tolerances.
* The US Government Accountability Office says that FDA tests less than one-tenth of 1 percent of imported fruits and vegetables, and less than 1 percent of domestic fruits and vegetables.