Last updated : April 21, 2025
In addition to pre-employment drug testing, the Department of Transportation (DOT) requires that all safety-sensitive employees submit to random, reasonable suspicion, and post-accident drug testing as required after hire. The drug testing procedure is well documented from start to finish to lessen the chance of error. Included in the process are regulations for laboratories approved for DOT testing. They operate under strict protocols and, therefore, adhere to the drug cutoff levels set by the DOT.
The levels lessen the chance of error, as well. They’re set high enough to protect employees from a false positive result. Certain over-the-counter (OTC) medications and even some foods can trigger false positive results. For instance, before the cutoff levels were changed to alleviate the problem, poppy seeds were notorious for causing people to test positive for opiates.
The debate whether or not poppy seeds can cause a false positive drug test result continues though. Some distributors overseas don’t properly wash off the opiate residue that remains on the seeds themselves.
If restaurants or bakeries purchase them, there is a possibility that someone could surpass the cutoff level. Moreover, some individuals intentionally purchase these seeds to make tea. Drinking it gets the drug into their systems—and as with any other method of ingestion—too much of it can result in death by overdose.
OTC medications that may cause false positive drug tests include cold medications with codeine. They can trigger false positive results for morphine. Even Ibuprofen taken in any form can sometimes cause false positive marijuana use.
What are cut-off levels?
Laboratories that process drug tests for the DOT are certified by the Substance Abuse and Mental Health Services Administration (SAMHSA). These laboratories follow DOT-mandated guidelines as to setting the amounts of drugs found in the test sample that trigger a positive result for a specific drug. If the level has a lower metabolite count than the level set, the test is negative. This eliminates the chance that trace amounts in the body, such as those caused by poppy seeds or ibuprofen, don’t cause false positive drug test results.
Specific drug test panels are added to create the requested drug test. While free to test for any drug, many employers of the general workforce use the DOT drug test as the basis for their company test.
The DOT tests for:
- Amphetamines and methamphetamines
- Cocaine
- Marijuana
- Opioids, including the synthetic opioids oxycontin, oxycodone, hydrocodone, and hydromorphone
- Phencyclidine (PCP)
The specifics
Below is a chart of the specific cutoff levels for each drug contained on the DOT drug test.
| Initial Test Analyte | Initial test cutoff | Confirmatory analyte | Confirmatory test cutoff concentration | |
| 1 | Marijuana Metabolites (THCA) | 50 ng/m | THCA | 15 ng/mL |
| 2 | Cocaine Metabolite (Benzoylecgonine) | 150 ng/mL | Benzoylecgonine | 100 ng/mL |
| 3 | Phencyclidine (PCP) | 25 ng/mL | Phencyclidine (PCP) | 25 ng/mL |
| 4 | Amphetamine | |||
| Amphetamine | 500 ng/m | Amphetamine | 250 ng/mL | |
| Methamphetamine | 500 ng/mL | Methamphetamine | 250 ng/mL | |
| MDMA/MDA | 500 ng/mL | MDMA/MDA | 250 ng/mL | |
| 5 | Opioids | |||
| Codeine/Morphine | 2000 ng/mL | Codeine/Morphine | 2000 ng/mL | |
| 6-Acetylmorphine (6AM or Heroin) | 10 ng/mL | 6-Acetylmorphine (6AM or Heroin) | 10 ng/mL | |
| Hydrocodone | 300 ng/mL | Hydrocodone | 100 ng/mL | |
| Hydromorphone | 300 ng/mL | Oxymorphone | 100 ng/mL | |
| Oxymorphone | 100 ng/mL | Oxymorphone | 100 ng/mL | |
| Oxycodone | 100 ng/mL | Oxycodone | 100 ng/mL |
The five panel drug test is constructed as mandated in DOT regulations 49 CFR part 40, Section 87.
DOT Drug Testing Methods Changing
The DOT enforces the Omnibus Transportation Employee Testing Act of 1991 which includes drug testing requirements for all agencies under its regulation. Until February 2022, the urine test was the only approved employee drug testing method.
That’s when the department announced its final ruling allowing employers to use the oral fluid drug test. As of yet, there are no SAMHSA-approved laboratories to process specimens. There must be two so that split-specimen protocol can be followed.
Moreover, proposed guide lines for DOT hair follicle testing are to be published in May 2025. Employers, employees, and others are encouraged to get involved in the process and voice their opinions—whether pro or con.
Eventually, the urine test may be completely removed from the DOT drug testing process. Time will tell. In the mean time, some employers are looking forward to using other test methods.
