Ever hear the phrase “contact high” or “second-hand high” and wonder exactly what it means? It’s a phenomenon by which inhaling other peoples’ cannabis smoke or vapor might get you high, whether you intended to or not.
Over the years “contact highs” have been depicted in movies leading to the idea that any amount of contact with 2nd-hand cannabis will get you high, but this simply isn’t the truth. Certain studies have shown that only in very specific conditions can someone possibly get a contact high.
Under the very specific conditions we’re going to describe, THC from second-hand smoke can actually enter the bloodstream and possibly even induce psychoactive effects. In today’s post, we’ll explore the meaning of a contact high, its potential effects, how and when it may happen, and other burning questions. Ready? Let’s get rolling!
What Is a Contact High?
A contact high happens when someone feels intoxicated simply from being in the same vicinity as other people who are smoking or vaping cannabis. For this phenomenon to occur, THC—the primary intoxicating cannabinoid in cannabis—must be inhaled by one person, exhaled into the air in the form of smoke or vapor, and then be inhaled again by somebody else close by. Additionally, it can happen through exposure to environmental smoke that is not being inhaled, like passive smoke coming off a joint, for example.
How Do Contact Highs Happen?
How are second-hand highs even possible? Isn’t all the THC absorbed by the person actually smoking or vaping? Not quite. While our lungs are pretty darn efficient at absorbing cannabinoids and other compounds, not everything is absorbed when we inhale cannabinoids. As mentioned, exposure also happens through the smoke that’s not inhaled.
With that said, while contact highs are possible, they’re really only likely in very specific conditions. Studies show that a secondhand high, with notable blood concentrations and signs of intoxication, may happen with prolonged exposure to smoke in an enclosed and non-ventilated space.
In a well-ventilated space, blood cannabinoid levels were much lower and did not produce intoxicating effects. In other words, the chances of a contact high are relatively low in a well-ventilated enclosed space and perhaps negligible when you’re outdoors.
Can a Contact High Make You Fail a Drug Test?
Speaking of drug tests, is it possible that someone with a high contact level—meaning someone who wasn’t actually smoking from a joint or pipe, or inhaling from a vape in the first place—to become intoxicated enough to trigger a positive result on a drug test?
A study from 2015 examined this very question. It found that the environment in which the cannabis is being consumed plays a large role in whether it ends up in the bloodstream of the non-smoker. Unventilated, enclosed interior rooms or spaces, in particular, were called out as being problematic, since they naturally tend to concentrate the smoke or vapor.
In the study, twelve participants were placed in a closed-off room, and half were asked to smoke ten joints of 11% THC cannabis. Afterward, detectable amounts of THC were found in the blood and urine of all subjects, and some performance impairment was detected on cognitive tasks.
The non-smokers also reported feeling pleasant, tired, and less alert, indicating that they did indeed catch some sort of second-hand intoxication. When the experiment was done again in a ventilated room, no THC was detected in the subjects who did not smoke. This indicates that ventilation and airflow are likely the most important than proximity when it comes to contact highs.
In general, while it’s unlikely that a person exposed to secondhand cannabis smoke will test positive for cannabis themselves, it isn’t impossible. As the study noted:
“Exposure to secondhand cannabis smoke under unventilated conditions produced detectable cannabinoid levels in blood and urine, minor increases in heart rate, mild to moderate self-reported sedative drug effects, and impaired performance on the Digit Symbol Substitution Task (DSST).”
While it is possible that extreme cannabis smoke exposure could produce a positive urine test, this occurrence is likely to be rare and limited to the hours immediately after exposure, according to the author of the study.
The takeaway: If you find yourself in the presence of a lot of cannabis smoke in an enclosed room—and you’re worried about the psychoactive (or legal) effects—remove yourself from the location.
Can You Get a Contact High From a Vape Pen?
Because they’re portable, discreet, and deliver a cooling mist rather than potentially irritating smoke, vapes are among the most popular dispensary items we stock (you can learn a bit more about them in this introductory article). But…is vapor any different than smoke when it comes to the possibility of a contact high?
Right now, that’s an open question. The studies that have explored cannabis contact highs have largely done so with smoke. Additionally, there are certain differences between smoke and vapor that may affect their ability to produce a second-hand high. For one thing, vapor is considered to be lighter than smoke and believed to dissipate much quicker.
As with the 2015 secondhand cannabis study, the environment in which the testing is done may play a major role. For instance, one study on e-cigarettes found that their use indoors significantly increased the amount of particulate matter in the air. That’s not hugely surprising in and of itself, but it does challenge the common belief that there are no (or very few) risks associated with vaping.
But out of doors, it may be a different story. That lightweight vapor simply may not linger around long enough to be inhaled by anyone else. That being said, there’s also no way to rule it out. At the end of the day, catching a contact high from vapor may also be possible under the right conditions.
Up till now, we’ve discussed vape pens in general. But can you get a contact high from a dab pen? Again, that’s an open question. Because the cannabis concentrates used in these specialized devices are so potent, you’d figure the risk of a secondhand high were greater. But again, it appears that—because of the very nature of those lightweight vapors—outside small closed environments, the risk isn’t hugely high of catching an unwanted buzz.
Be Mindful of Your Smoke and Vapor
Even if it appears to be difficult to catch a contact high from smoke or vapor, you should still be considerate to others when enjoying a joint or a vape pen. Some folks may be worried about smelling like cannabis or about smoke irritating their eyes, and some people simply don’t like being exposed to any form of smoke, even cannabis.
Learn More About This Feel-Good Plant with Green Goods
At Green Goods, we’re passionate about connecting our customers with real, trustworthy, and authoritative information on cannabis and how to get the most of it. If you want to take a deep dive on such topics as full-spectrum CBD, hybrid cannabis strains, and the real difference between indica and sativa, start at our Cannabis Education blog.
And if you’re looking to connect with top-notch cannabis in a fun, friendly, and supportive environment, visit our family of Maryland and Minnesota dispensaries. Whether you’re interested in the potential of medical cannabis to change people’s lives for the better—or just kicking back and relaxing with friends and family—we’ve got what you’re looking for.
