Drug testing is a critical tool for maintaining workplace safety and compliance. Understanding cut-off levels and detection periods is essential for interpreting results accurately and making informed decisions.
What Are Cut-Off Levels?
Cut-off levels are the minimum concentrations of a substance required to trigger a positive result in a drug test. If the concentration is below this threshold, the result is negative, even if traces of the substance are present.Â
These thresholds vary by substance and test type:
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Marijuana metabolites: 50 ng/mL (initial), 15 ng/mL (confirmatory)
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Cocaine metabolites: 150 ng/mL (initial), 100 ng/mL (confirmatory)
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Amphetamines: 500 ng/mL (initial), 250 ng/mL (confirmatory).
Lower cut-off levels increase sensitivity but may lead to false positives, while higher thresholds reduce false positives but may miss low-level use.
Detection Periods by Substance
Detection periods depend on the substance, frequency of use, and test type. Common detection windows include:
| Drug | Abbrev. | Urine | Oral Fluid | Hair (pg/mg) |
|---|---|---|---|---|
| Alcohol | ETOH | - | > 0.02% | - |
| Amphetamine | AMP | 1000 / 300 | 500 | 500 |
| Barbiturates | BAR | 300 | 300 | - |
| Bath Salts | BSA | - | 1000 | - |
| Benzodiazepines | BZO | 300 | 50 | TBD |
| Buprenorphine | BUP | 10 | 10 | TBD |
| Clonazepam | CLZP | - | 300 | - |
| Cocaine | COC | 300 | 50 | 500 |
| Cotinine | COT | 200* | 30 | - |
| Ecstasy (MDMA) | MDMA | 500 | 100 | - |
| Ethyl Glucuronide | ETG | - | - | - |
| Fentanyl | FEN | - | 200 | TBD |
| Gabapentin | GAB | - | - | - |
| Hydrocodone | HYD | - | - | - |
| Ketamine | KET | - | 1000 | - |
| Kratom | KRA | 50** | 300 | 100*** |
| Marijuana (THC) | THC | 1000 / 500 | 7525*** | 500 |
| Methamphetamine | MAMP | 300 | 500 | TBD |
| Methadone | MTD | - | 75 | - |
| Methadone Metabolite | EDDP | - | - | - |
| Methaqualone | MQL | - | 300 | - |
| 6-Monoacetylmorphine | 6MAM | - | 10 | - |
| Opiates / Morphine | OPI / MOR | 2000 / 300 | 50 | 200 |
| Oxycodone | OXY | 100 | 50 | TBD |
| Phencyclidine (PCP) | PCP | 25 | 10 | 300 |
| Propoxyphene | PPX | 300 | - | - |
| Synthetic Cannabinoids (K2) | K2 | - | 50 | - |
| Tramadol | TRA | - | 200 | - |
| Tricyclic Antidepressants | TCA | 1000 | - | - |
** Kratom values are not standardized
*** Hair and oral fluid thresholds are based on select lab data
TBD = To Be Determined
Values may vary by test type and individual metabolism.
Hair testing offers the longest detection window, while saliva testing identifies recent use 6 10 13.
Why These Metrics Matter
Employers rely on cut-off levels and detection periods to balance accuracy with fairness. For example:
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Urine tests are cost-effective and widely used.
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Saliva tests detect recent use, ideal for post-incident testing.
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Hair tests provide a long-term usage overview.
Final Thoughts: Making Informed Decisions
Understanding cut-off levels and detection periods is key to interpreting drug test results correctly and applying them fairly in the workplace, healthcare, or legal settings. By aligning the right test type with your organization’s goals—whether it’s immediate detection, long-term monitoring, or compliance assurance—you can strike the right balance between accuracy, efficiency, and trust.
At DrugScreens.com, we provide FDA-cleared, CLIA-waived drug testing kits designed to meet the highest standards of reliability. From urine and saliva tests to hair and specialty panels, our solutions help employers, clinics, and agencies make confident, compliant decisions.
👉 Explore our full range of drug testing kits today—and ensure your program has the tools it needs to protect people, workplaces, and communities.
