Medically reviewed by Carmen Fookes, BPharm. Last updated on Oct 30, 2019.
Federal workplace cutoff values for marijuana metabolites are 50 ng/mL for immunoassay screening tests (one ng is a billionth of a gram). In a confirmatory test, a metabolite of marijuana is measured, called delta-9-tetrahydrocannabinol-9-carboxylic acid, and a positive test result is above 15 ng/mL. However, this can vary depending on the variables listed above and should not be relied upon to ensure a drug-free result.
An estimate of the length of time marijuana (THC) is detectable in urine is:
Drug testing can be conducted on various biological specimens, such as urine, hair, blood, saliva, sweat, toenails, fingernails, and meconium. Urine drug testing is the most common way of workplace testing for specific drugs because it is not invasive, and samples are easy to collect.
Theoretically, CBD should not show up on a drug test. However, because most CBD products are classified as a supplement, it is not regulated for safety and purity. This means that contamination of the CBD with THC (tetrahydrocannabinol) may and does occur, and this may show up on a drug test, depending on the cutoff level of the test and other factors listed below.
Cannabidiol (CBD) has recently surged into the therapeutic spotlight for its perceived anti-inflammatory, anti-anxiety, pain-relieving, and seizure-suppressing properties. CBD products can be found in health and wellness aisles across the world — perhaps even at your local Walgreens or CVS — in many forms, some of which include CBD oil, tinctures, edibles, elixirs, and more.
Recognized as the preferred method for cannabis drug testing, urine screenings are often used as a benchmark to detect for cannabis use. Most urine tests utilize a specific sensitivity for the cutoff concentration of THC-COOH. The most common cutoff concentration point is 50 nanograms per milliliter (ng/mL), as suggested by the Substance Abuse and Mental Health Services Administration (SAMHSA).
How to consume CBD without THC
Upon inhalation, active THC can be found in the bloodstream within a matter of seconds and can be detected in plasma for several hours, depending on the frequency of use and dosage. According to a 2004 review published in the journal Therapeutic Drug Monitoring, the plasma concentration of THC peaks just three to eight minutes after inhalation and then decreases quickly with a half-life of about 30 minutes. The study claims that THC is detectable in blood for about five hours, but the THC metabolite THC-COOH has a detection time of up to 25 days.
THC and its metabolites can also be detected in the saliva of occasional and chronic users. A 2014 study published in the journal Drug Testing and Analysis looked at cannabinoids in oral fluid and found that THC metabolites were detectable in the saliva of occasional users for one to three days and chronic users for up to 29 days.
CBD is a non-intoxicating cannabinoid found in cannabis plants, and some say it provides the benefit of relaxation without THC’s high.
Very small amounts of THC present in the material that CBD is extracted from can get into the CBD oil in high enough amounts to result in a positive drug test. This scenario may be more apt to occur when CBD oil is purchased from cannabis dispensaries in places where cannabis is legal, as opposed to an online retailer.
Some sources report that in rare cases, false positive test results have come from CBD oil that breaks down into very small amounts of THC in the stomach. Other studies, however, have refuted this.
Most CBD products are made from hemp, not marijuana.
3. Mislabeling of Products
Cannabis is the umbrella term describing hemp and marijuana plants—two different varieties of the cannabis genus. Both marijuana and hemp can be described as cannabis plants; however, it is important to note that they are still two separate plants.
Inadvertent exposure to marijuana (via secondhand smoke) is unlikely to be enough for a person to get a positive drug test result, but it is possible. Being in a room with heavy pot smokers for several hours may cause the inhalation of enough THC containing smoke to result in a positive test.
When a drug test is performed, the active chemical in marijuana that gets detected in a positive screening is THC. However, most people are under the impression that CBD oil is THC-free.
However, the distinction between full spectrum oils and isolates make all the difference if you are being tested for drug use.