What are drug testing cut off levels?

Drug testing cut-off levels are the minimum concentrations of specific drugs or their metabolites that must be present in a sample (such as urine, blood, saliva, or hair) for the test to be considered positive. These levels are established to prevent false-positive results and ensure that only trace amounts of a substance are not misinterpreted as drug use.

Cut-off levels vary depending on the specific drug being tested, the type of test being used, and the guidelines followed by the testing laboratory or organization. For example, the Substance Abuse and Mental Health Services Administration (SAMHSA) in the United States has established specific cut-off levels for various drugs in workplace drug testing programs. Some common SAMHSA cut-off levels for urine testing include:

1. Amphetamines: 500 ng/mL
2. Cocaine metabolite (Benzoylecgonine): 150 ng/mL
3. Opiates (Morphine and Codeine): 2000 ng/mL
4. Phencyclidine (PCP): 25 ng/mL
5. Marijuana metabolite (THC-COOH): 50 ng/mL

These cut-off levels are subject to change and may vary among different testing methods or organizations. Understanding the specific cut-off levels established by the testing body when interpreting drug test results is essential.