smelling weed drug test

What Are the Side Effects of Secondhand Marijuana Smoke?

Marijuana smoke is created whenever someone burns the leaves, flowers, stems, or seeds of the cannabis plant. Marijuana is used by an average of 26 million Americans per month. It’s been studied for some medical uses.

But despite marijuana’s prevalence, its safety is sometimes in dispute. Smoking it, or being near someone else who is smoking it, does cause side effects.

Marijuana contains a chemical called THC, which can block pain and bring on a feeling of relaxation to people who breathe it in or consume it. Smoking weed has depressant, hallucinogenic, and stimulant effects. Inhaling THC can also impair your ability to concentrate and to operate a car.

Whenever you’re breathing in THC, it’s possible to get high. Effects of THC vary from person to person, as well as how much of the chemical you’re exposed to.

Drug test results can differ for people who are exposed to secondhand marijuana smoke and people who smoked marijuana.

In 2015, a small study of six smokers and six nonsmokers showed that marijuana smoked in highly concentrated quantities could trigger a positive urine drug test among people who were simply exposed to the smoke in an unventilated room.

However, ventilation during marijuana exposure, as well as how often exposure occurred, were critical factors in what the drug test result would be.

For example, smelling marijuana smoke in passing once in a while is a lot different from living with a habitual marijuana smoker who uses marijuana in your presence regularly.

Another small study attempted to mimic a more true-to-life example.

Rather than stick nonsmokers in a closed, unventilated room for long smoking sessions, these study participants spent three hours in a coffee shop where other patrons were smoking marijuana cigarettes.

After their exposure to secondhand marijuana smoke, participants were tested for THC. While a trace amount of THC did show up in their blood and urine, it wasn’t enough to trigger a positive drug test result.

It was unlikely that any contact high was passed during this study.

With that being said, getting a contact high is possible.

Being near marijuana smoke often and in poorly ventilated areas (like a car with the windows rolled up or a small bedroom without a fan) may result in feeling a limited amount of the effects that the person smoking experiences.

But catching a whiff of marijuana fragrance through your apartment window or entering a room where people were smoking several hours ago is very unlikely (maybe even impossible) to affect you at all.

There isn’t much by way of clinical data to understand if secondhand marijuana smoke is as bad for your health as tobacco smoke.

According to the American Lung Association, regularly smoking marijuana yourself can damage your lungs and weaken your immune system.

And a 2016 study on rats showed that just one minute of secondhand marijuana smoke impaired lung function for at least 90 minutes — which is longer than the lungs are affected by tobacco secondhand smoke.

Secondhand marijuana smoke exposes you to many of the same toxic chemicals as smoking it directly does. Because of this, the American Lung association recommends that people avoid exposure to secondhand marijuana smoke.

Contact high may be less common than we think, but it’s possible. Here are some of the other side effects and symptoms of secondhand marijuana smoke exposure.

Delayed reflexes

Smoking weed can slow your reaction time when you’re on the road. If you have high levels of THC in your blood from secondhand marijuana smoke, it might have the same effect.


If you’re around marijuana smoke for a long period of time, you may begin to feel lightheaded or dizzy.


One effect of the THC in marijuana is the feeling of calmness it gives some users. For others, this calmness can take the form of feeling tired or lethargic.


Researchers are still trying to understand the connection between excessive marijuana exposure and mental health. It appears that marijuana use can trigger or worsen some mental health conditions, including depression.

No link has been established between secondhand smoke marijuana exposure and depression.

The legal and medical use of marijuana is changing rapidly, but that doesn't mean it's safe for everyone to be exposed to it. Here's what you need to know.

Can You Fail a Drug Test from Secondhand Weed Smoke?

People are often concerned about the possible psychoactive effects of secondhand marijuana smoke, especially if they have an upcoming drug test. For years, cannabis has been linked to various misconceptions. For that reason, secondhand weed smoke is also believed to be connected with dangerous consequences.

Since pot has increased in popularity, scientists have decided to investigate its effects and influence of secondhand smoke. Researchers measured the concentration of THC in the blood of people who don’t smoke weed.

In most cases, they managed to agree on the same things. But, So, let’s see what results they were able to find out, and how passive exposure affects your health?

Very detailed information and guidelines about passing any drug tests can be found at the THC Authority website if you are interested into this topic.

Can You Fail a Drug Test When Inhaling Secondhand Weed Smoke?

Based on numerous studies, a minimal amount of THC is released into the air when smoke is exhaled. In facts, even if you stayed in a room where four people smoked weed, you wouldn’t get high, nor show signs of intoxication.

However, you’ll have to be trapped with 16 people smoking joints, for the results to show the traces of THC in your bloodstream. But, let’s move to the most concerning part, can you fail a drug test from smelling weed? Probably not!

Considering the low concentration of THC is being released into the air, you would have to take a lot of secondhand exposure to fail this screening. Based on some study in 2010, scientists measured the influence of secondhand marijuana smoke on non-smokers.

The participants were placed in a well-ventilated room with people who casually smoked weed for three hours. After the procedure was over, the technicians took blood and urine samples from non-smokers.

They found the traces of TCH, but not a sufficient amount to fail a drug test. Another study came up with similar results. In rare cases, testing can be positive, but the person needs to be exposed to marijuana smoke for hours.

What Is Passive Exposure?

When you go through a urine test for weed, it examines the by-products of THC. This chemical is responsible for psychoactive effects and positive results. However, people are often under the impression that even the slightest contact is enough for the THC to show up in the urine.

Secondhand smoke is another term for passive exposure. It means that you aren’t inhaling TCH directly from the source, which makes a significant difference. The amount you inhale is minimal, nearly 100 times less than THC levels from the direct source.

In that case, if you haven’t been smoking pot, then drug test shouldn’t be a concern. So, if you are wondering, can you fail a drug test from being around weed, no, you can’t.

Are There Any Health Risks Connected to Secondhand Marijuana Smoke?

We still don’t have reliable data regarding health risks, and we don’t know if the person who lives with regular pot smoker is affected. The most challenging part is to determine the amount of THC released into the air.

Some recent studies suggest that secondhand marijuana smoke has similar health effects as secondhand tobacco smoke, mostly on heart and blood vessels. However, this study has not been conducted on humans, so we can’t claim with certainty they have similar results.

Same as cigarettes, the pot contains harmful and cancer-causing chemicals, but we still don’t know how they affect the person’s health.

You have to be aware of the fact that any kind of smoke inhalation carries a particular risk. But, if you are worried about an occasional friend gathering, don’t be. Marijuana secondhand smoke can’t kill you, nor cause any significant health issues.

Can You Fail a Drug Test from Secondhand Weed Smoke? People are often concerned about the possible psychoactive effects of secondhand marijuana smoke, especially if they have an upcoming drug