Can You Fail a Drug Test from Secondhand Smoke?
Despite the rising profile of marijuana, cannabis remains federally prohibited. While 37 states have medical marijuana programs, many laws and rules limiting cannabis use remain in place today. Secondhand marijuana smoke is a valid concern if you or someone you love is a medical marijuana patient.
Many employers and other institutions routinely test applicants and employees for drugs as a component of their screening and workplace drug testing processes. If you rely on cannabis to manage the symptoms of a chronic condition, you must be vigilant about who you smoke around. A positive test can potentially preclude a non-smoker from jobs and other opportunities.
Marijuana smoke contains tetrahydrocannabinol (THC) and other compounds that give cannabis its psychoactive and medicinal effects. THC is also the compound in marijuana that triggers positive drug tests. This article explains how secondhand cannabis smoke affects people, the odds of a positive due to secondhand smoke, and tips for minimizing exposure to it.
What is Secondhand Smoke?
Burning marijuana leaves, flowers, stems, or seeds creates smoke. Inhaling through a joint or pipe causes the intoxicating high sought by recreational users and delivers the symptom control sought by medical marijuana patients.
Like secondhand cigarette smoke, marijuana smoke mingles with the air. Those near the person consuming cannabis can inhale it. As a result, you ingest tar, some of the cannabinoids contained in marijuana, and other chemicals. As with cigarettes, prolonged and frequent exposure to secondhand smoke can harm the lungs.
Every substance that enters the human body produces side effects. Anyone in proximity to the smoke can inhale it. This susceptibility makes it especially important to avoid smoking marijuana around pregnant women, children, individuals with mental health conditions, and those with pre-existing respiratory issues.
Can Secondhand Smoke Make You Fail a Drug Test?
Secondhand marijuana smoke could make you fail a drug test, but the risk is considered remote. That doesn’t mean you should dismiss the effects of secondhand smoke, however. As with many aspects of marijuana use, research is limited due to the ongoing federal prohibition of cannabis.
Ingesting high enough levels of THC from secondhand marijuana smoke can result in a “contact high.” In this situation, you experience a mild form of marijuana’s psychoactive effects due to passive exposure.
A recent Canadian scientific literature review of 15 articles found evidence that cannabinoid metabolites are present in the bodily fluids of those exposed to secondhand marijuana smoke.
While infrequent and brief exposure to secondhand marijuana smoke is unlikely to trigger a positive drug test, it is possible. Exposure to secondhand marijuana smoke in a poorly-ventilated or unventilated room or over a prolonged period increases the amount and concentration of the inhaled smoke. More cannabinoids, like THC, will enter the bloodstream, increasing the likelihood of a positive urine test.
Organizations that conduct drug screening and have zero-tolerance marijuana policies may detect various amounts of THC in your drug test results. Studies show that THC from secondhand smoke can remain in a person’s system for up to 48 hours, which could produce a positive result. Considering the high potency of the medical cannabis on the market today, secondhand smoke exposure may contain high levels of THC, thus elevating your risk of a failed drug test.
Effects of Firsthand vs. Secondhand Smoke
Firsthand marijuana smoke, inhaled from a joint or a device, delivers concentrated smoke directly to your lungs. Inhalation of medical marijuana has the fastest-acting and usually most intense effects.
Many patients rely on smoking for rapid relief of pronounced systems because the THC quickly enters the blood. Beyond symptom relief, firsthand smoke can cause red eyes, euphoric feelings, hunger, an altered sense of time, and dampened motor skills.
The longevity and intensity of firsthand smoke’s effects result from an individual’s biochemistry, experience with cannabis, and the strain of marijuana. In general, smokers first feel marijuana’s effects within 10 minutes of inhalation.
They peak after about three hours. The effects linger for up to 10 hours. Frequent cannabis users can have detectable levels of THC in their urine for up to 30 days after they stop using marijuana.
Secondhand smoke has the same but milder effects as firsthand smoke. You may experience itchy or red eyes, dry mouth, headache, and elevated heart rate. These are common and resolve once your body metabolizes the cannabinoids in the smoke.
Depending on the longevity of your exposure and the potency of the marijuana, you could experience anxiety, euphoria, restlessness, or paranoia. In rare cases, secondhand smoke can alter your memory or motor skills.
Be sure to exercise caution after exposure to secondhand marijuana smoke for an extended period or if you live with a medical marijuana patient. Secondhand smoke could impair your ability to drive or perform potentially dangerous activities, like those requiring power tools or heavy equipment.
Generally, the detectable levels of THC that could trigger a positive drug test are gone within 24 hours of exposure to secondhand marijuana smoke.
How to Avoid Secondhand Smoke
The only surefire way to avoid secondhand smoke is to avoid sharing an enclosed space with someone while they smoke marijuana and for a while after they finish. The smoke lingers in the air even after the marijuana is extinguished and can permeate surfaces and fabrics, exposing you to thirdhand smoke.
If you live with a medical marijuana patient, designating a well-ventilated area for smoking can help isolate the smoke and increase its dissipation rate. Fans and open windows can replace marijuana smoke with fresh air, reducing exposure.
Smoking outdoors can further minimize the risk of secondhand smoke. Sitting upwind of the smoker will reduce the chance of smoke blowing toward you. Be sure to verify local laws and ordinances to ensure using marijuana outside is legal.
Depending on the nature of the patient’s symptoms, they can talk to their medical marijuana doctor or the staff at their dispensary about alternative consumption methods. Edibles, tinctures, concentrate, and topicals provide THC and can effectively manage symptoms. However, each form has varying levels of effectiveness for different symptoms, onset times, and durations.
Kirstie is a Certified Cannabis Coach with over 10 years in the medical cannabis field. She has worked at The Sanctuary Wellness institute since 2021 and has helped countless patients with questions pertaining to medical cannabis.