How Long Does Secondhand Smoke Stay In Your System?

Cannabis is becoming legal in more places, and more people are using it — but what about the smoke? Have you ever wondered if being around someone else’s cannabis smoke can affect you? To help you learn more, we’ll explore further into the topic of secondhand cannabis smoke. We’ll discuss what it is, how it can get into your system, and how long it stays there. 

Having a basic understanding of these effects is important for everyone, whether you use cannabis or not. Plus, there’s lots of misinformation out there that needs to be addressed. So, let’s find out what secondhand cannabis smoke really does and how you can protect others around you.

What is Secondhand Cannabis Smoke?

Secondhand cannabis smoke is the smoke you breathe in when someone else is smoking cannabis near you. It’s similar to secondhand tobacco smoke, but there are some key differences. Both types of smoke can be harmful because they contain various similar chemicals, particularly depending on what was used to roll the cannabis. 

However, cannabis smoke contains THC (tetrahydrocannabinol), the element that makes people feel “high” and opens the airways. When you breathe in secondhand cannabis smoke, some minuscule amounts of THC can enter your body. Depending on the amount and duration of exposure, this might make you feel different, even if you’re not the one smoking. 

Many people report experiencing a “contact high,” where they feel the effects of THC just by being around cannabis smoke. It’s not clear if that is a placebo high or actual high, since the amounts of THC transferred are nearly negligible.

What Factors Influence Secondhand Smoke Ingestion?

Several factors influence how much secondhand cannabis smoke you might ingest, including: 

• Environment: Whether you are indoors or outdoors makes a big difference. Smoke lingers longer in closed spaces, so you might breathe in more THC if you are indoors.
• Duration of Exposure: The length of time you spend around smoke affects how much you take in. The longer you stay in a smoky area, the more THC you might absorb.
• Ventilation: Good air circulation can reduce the amount of smoke you inhale. Rooms with fans or open windows allow smoke to dissipate, lowering your exposure.
• Proximity: How close you are to the person smoking matters. The closer you are, the more smoke you are likely to breathe in.
• Frequency: If you are regularly exposed to secondhand smoke, you might ingest more THC over time compared to occasional exposure.

Can Secondhand Smoke Make Me Fail A Drug Test?

One common concern is whether secondhand cannabis smoke can cause you to fail a drug test. While it is improbable, it is technically not impossible. A recent study suggests that it is unlikely for someone exposed to secondhand weed smoke to test positive for THC. Although extreme exposure to cannabis smoke could result in a positive urine test, researchers from Johns Hopkins University indicate that such cases are rare and usually only occur within a few hours after exposure.

According to the study, published in the Journal of Analytical Toxicology, six regular cannabis users smoked cannabis with different THC levels in a confined space, while six non-smokers sat nearby. The sessions took place in both unventilated and ventilated rooms. The non-smokers had their urine tested 13 times over 34 hours. Only one non-smoker’s urine showed THC metabolite (THC-COOH) levels above the typical detectable limit of 50 ng/mL, occurring four to six hours after exposure. 

Using an additional highly sensitive test of 20 ng/mL, which isn’t standard for workplace drug testing, researchers found much lower THC-COOH levels detectable for up to 24 hours in multiple participants. In the ventilated room, non-smokers did not reach the threshold for a positive drug test. Therefore, it’s reasonable to conclude that casual secondhand exposure to cannabis smoke will generally not make you fail a standard urine drug test.

How Long Does Secondhand Weed Smoke Stay in Your System?

Secondhand weed smoke doesn’t stay in your system for long, especially compared to direct cannabis use. For most people, any THC absorbed from secondhand smoke is processed and eliminated within a few hours to a couple of days. 

Even in cases of heavy exposure, detectable levels usually drop quickly. As a result, you can feel reassured that brief, occasional exposure to secondhand cannabis smoke is unlikely to have any lasting impact on your system. Just note the data are limited here, but so far indicate negligible, temporary impacts. 

What Are Some Health Complications of Secondhand Cannabis Smoke for the Non-Smoker?

Secondhand cannabis smoke can cause several health complications for non-smokers. Just like with tobacco smoke, breathing in cannabis smoke can irritate the lungs and airways, leading to coughing and respiratory discomfort. Over time, repeated exposure may increase the risk of developing bronchitis, asthma exacerbation, and other lung issues. Also, there isn’t any data to show smoking cannabis causes lung cancer.

Secondhand cannabis smoke can also have immediate effects, such as dizziness, headaches, and nausea, especially in enclosed or poorly ventilated areas. For vulnerable populations such as children, pets, pregnant people, the elderly, the disabled, or people with pre-existing respiratory conditions, these risks are even greater. Infants exposed to any kind of second-hand smoke run a higher risk of SIDS, largely because of the toxic components in the smoke.

Practical Tips for Minimizing Exposure

There are some easy ways to reduce your exposure to secondhand cannabis smoke. First, make sure there is good ventilation. Open windows and use fans to keep the air moving, which helps clear out the smoke and reduces the amount you breathe in. Remember not to point it at your neighbors. 

Next, try to keep smoking activities separate from common areas. Be courteous by designating specific areas for smoking, preferably outdoors, to keep the smoke away from places where non-smokers gather. In addition, it’s important to educate your friends and family about the effects of secondhand smoke. Let them know how it can affect vulnerable non-smokers and encourage them to be mindful of where they smoke. 

Final Thoughts

Being aware of the effects of secondhand cannabis smoke is important for everyone, whether you use cannabis or not. While secondhand cannabis smoke can carry risks, it is generally not as dangerous as secondhand tobacco smoke. Additionally, there are many ways to enjoy cannabis that do not involve smoking. Edibles, tinctures, topicals, and vaporizers are all options that eliminate many of the risks associated with smoke. 

By staying informed and taking practical steps to minimize exposure, you can enjoy the benefits of cannabis while protecting your health and the health of those around you. Awareness and prevention are key, and with the variety of consumption methods available today, it’s easier than ever to make safe and healthy choices.

Note: The content on this page is for informational purposes only and is not intended to be professional medical advice. Do not attempt to self-diagnose or prescribe treatment based on the information provided. Always consult a physician before making any decision on the treatment of a medical condition.