What does “not detected” mean in food pesticide tests?
In USDA pesticide testing of food, “not detected” means the sample was tested for an analyte without a validated detection. It does not prove that the pesticide or other analyte is completely absent.
Three different results
- Detected
- The laboratory reported a detection of the substance it tested for. This is not a food-safety score.
- Tested, with no reported detection
- A test was performed without a validated detection. This does not prove the substance was absent.
- Not tested or not covered here
- No validated test is available for this comparison. Do not count missing coverage as a nondetection.
Illustrative example, not USDA results: imagine 10 samples with validated tests for one analyte. Three have detections and seven do not: the detection rate is 3 out of 10, or 30%. Samples without a validated test for that analyte do not enter this rate.
Detection limits depend on the test
A limit of detection (LOD) describes the sensitivity of a laboratory test. Limits differ across analytes, foods and methods, and can change over time. We keep the laboratory outcome and source annotations, including reported detections below the listed LOD; we do not replace them with a rule based only on concentration.
“Not tested” means no validated test is available in this release. Missing coverage is never counted as a negative result. Unvalidated NU records are retained but excluded from validated test counts and percentages.
A nondetection is a laboratory result, not proof of absence or a food-safety conclusion.
Explore pesticide test results in food
See tested samples, detections and coverage for strawberries, apples, or browse all foods.
Read the counting rules and testing coverage. USDA documents LOD fields in its PDP data dictionary.