The head of the U.S. Department of Agriculture’s organic program reminded growers in a blog that certifying agents now must do residue tests on products from a minimum of 5% of the operations they certify as part of the agency’s stepped up enforcement efforts.

National Organic Program deputy administrator Miles McEvoy said in the blog entry the testing will help certifying agents take enforcement action against farms and businesses intentionally using prohibited substances or methods. He said agents can also use test results to identify and address instances in which organic products may have unintentionally come in contact with prohibited substances.

Certifying agents will continue to determine which organic operations should be tested, McEvoy said.

“Some testing will likely be random, while other testing will be risk-based,” McEvoy’s blog states. “Since there will be wide variety in how organic operations are selected and which tests are conducted, test results will not be used to make broad conclusions about a specific commodity or category of products.”

The mandated minimum testing, which began Jan. 1, should increase consumer confidence as well as confidence in the integrity of USDA organic products among international trade partners, McEvoy said.