Drug Testing in the Workplace
Drug testing cutoff levels are the minimum concentrations of drugs or metabolites that must be present in specimens, before labs will report the drug testing results as positive. How much of a drug labs can detect depends on drug detection times, frequency of use, type of specimen, drug testing method, metabolism, and other factors.
Labs that follow the Mandatory Guidelines for Federal Workplace Drug Testing Programs published by the Substance Abuse and Mental Health Services Administration (SAMHSA), first conduct one or more initial screens followed by confirmatory tests. The approved methods for urine analysis are one or more types of immunoassay (IA) screens, confirmed by gas chromatography and mass spectrometry (GC/MS). If you test below the drug cutoff levels on the initial screens, the lab cannot report it as positive or continue with the confirmatory tests. If you test above them on the initial screens, but below them on the confirmatory test, the lab still cannot report it as positive.
Basic testing typically screens for the following, commonly-abused drugs.
- Amphetamines (speed, meth, crank, ecstasy)
- Cannabinoids (marijuana, hash)
- Cocaine (coke, crack)
- Opiates (heroin, morphine, opium, codeine)
- Phencyclidine (PCP)
Extended testing might also screen for some or all of the following, but basic testing is the most common.
- Barbiturates (phenobarbital, butalbital, secobarbital)
- Benzodiazepines (tranquilizers like Valium, Librium, Xanax)
- Ethanol (ethyl alcohol, booze)
- Hallucinogens (LSD, mushrooms, mescaline, peyote)
- Inhalants (paint, glue, hair spray)
- Anabolic Steroids (synthesized, muscle-building hormones)
The tables below are compiled from public-domain information in the Mandatory Guidelines for Federal Workplace Drug Testing Programs. (See Notes below.) They are for urine analysis of the commonly-abused types of drugs known as the "SAMHSA Five."
Initial Drug Cutoff Levels
Nanograms per Milliliter (ng/ml)
Opiate metabolites 1
1 Labs are permitted to initial test all specimens for 6-acetylmorphine at a 10 ng/ml cutoff
2 Target analyte must be d-methamphetamine and the test must significantly cross-react with MDMA, MDA, and MDEA
Confirmatory Drug Cutoff Levels
Nanograms per Milliliter (ng/ml)
Marijuana metabolite 1
Cocaine metabolite 2
1 Delta-9-tetrahydrocannabinol-9-carboxylic acid
3 Specimen must also contain d-amphetamine at a concentration > 100 ng/ml
4 Labs test for 6-acetylmorphine when the morphine concentration exceeds 2,000 ng/ml
As of September 3, 2001, SAMHSA last revised these cutoff levels in 1998 and considers them sound. For the full text of the guidelines and tips about searching for revisions, see Mandatory Federal Guidelines.
Other government entities might have their own specifications that differ from those above. See Mandatory Federal Guidelines for more information and links.
If you've never or rarely abused drugs, but happen to get some into your system close to the time you submit your specimen, like at a party where pot smoke fills the air, you'll come in at only about 5 ng/ml for marijuana metabolites. That's well below the cutoff level of 50 ng/ml, so you're safe. The tests are only for illegal drug use, too. If you're on legit prescription medications and have normal levels for such, you have nothing to fear. But if you're royally screwing up on the job because of your medication or the condition you're medicating, you might have to take medical or disability leave.
6-acetylmorphine (6-AM) is a heroin metabolite and also called 6-monoacetylmorphine (6-MAM). 6-AM is rapidly metabolized to morphine, so will not likely be detected in most urine specimens. But of course, morphine will likely be detected after recent heroin use. Because codeine is a naturally-occurring alkaloid in the opium poppy juice that is the source of morphine and heroin, it too might be in the urine of heroin users.
Codeine is rapidly metabolized and excreted in urine as codeine, morphine, or both. Morphine is a metabolite of codeine, but not the other way around, so ingestion of morphine will not account for the presence of codeine.
The chemical names for the most-common forms of amphetamines are d-amphetamine and d-methamphetamine.
MDMA, MDA and MDEA are methylene-dioxy derivatives of amphetamine and methamphetamine. They are the so-called "designer drugs" commonly known as Ecstasy, X, XTC, etc.