Glossary

Cutoff level

The concentration threshold at or above which a sample is reported as non-negative.

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Cutoff levels exist for both the initial screening step (immunoassay) and the confirmation step (mass spectrometry). They are set by federal guidelines (SAMHSA / DOT) for regulated programs and may be lower or higher in non-regulated programs depending on the testing context.

Sources & references

drugtest.co content is sourced from primary regulatory and clinical references. We do not cite gray-market or "how to pass" sources.

  1. Mandatory Guidelines for Federal Workplace Drug Testing Programs (Urine) — SAMHSA
  2. 49 CFR Part 40 — Procedures for Transportation Workplace Drug and Alcohol Testing Programs — U.S. Department of Transportation

Related terms & pages

Glossary

Immunoassay

The initial screening method that uses antibodies to detect drug classes — fast but less specific than confirmation.

 Glossary

GC-MS (gas chromatography–mass spectrometry)

A confirmation method that separates and identifies individual analytes by mass-to-charge ratio.

 Glossary

LC-MS/MS (liquid chromatography–tandem mass spectrometry)

A confirmation method that uses two stages of mass analysis, often used for fentanyl and other low-cutoff analytes.