limit of detection
The lowest concentration of a substance that can be detected using standard tests but which is too small to be measured with certainty
In food safety, the limit of detection (LOD) is the lowest concentration of a substance—such as a contaminant, chemical residue, or pathogen—that an analytical method can reliably detect, though not necessarily quantify. If a substance is present below this level, it may go unnoticed. LOD reflects the sensitivity of a test and helps define when a substance can be considered absent or below a relevant threshold.
EFSA uses the LOD to assess exposure to low-level contaminants, handle “non-detects” in dietary data, and ensure analytical methods are robust and fit for purpose. It also informs the setting and enforcement of regulatory limits, such as maximum levels for contaminants or residues, supporting accurate risk assessment and consumer protection.