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Can Someone Get High From, And Fail A Drug Test For, Secondhand Marijuana Smoke?


marijuana contact high secondhand smokeIf you are a veteran marijuana consumer, you have heard of the term ‘contact high’ a lot I’m sure. Maybe you had a friend that was hanging out with you while you were smoking, and they were certain that they had a ‘contact high’ from being around you while you were puffing. Or maybe you knew someone that failed a drug test, and swore that they had never smoked marijuana themselves, but were around people that were. That was the case with NFL player Josh Gordon, who was suspended from the NFL for barely failing a chemical test for marijuana.

For a long time marijuana consumers, and non-marijuana consumers for that matter, were left to wonder if those scenarios were even possible. I know I have hung out with people before that didn’t smoke marijuana, and although they felt like there were getting a contact high, I was pretty sure they were just lame and trying to over embellish. I have heard of many people that have failed drug tests and swore that they didn’t smoke, and I have always wanted to see the science behind what it would take to fail a drug test due to being around second hand marijuana smoke.


Being around enough second hand marijuana smoke to ‘get high’ is a different question than how much marijuana smoke someone would need to be around to fail a drug test. Being ‘high’ is subjective, while the amount of THC in ones system is quantifiable with a chemical test. Just because I have above a threshold for THC in my system doesn’t mean that I’m high at the time of the test because marijuana can stay in someone’s system for a long time, which is something that is common knowledge to anyone who knows anything about marijuana.

Can someone fail a drug test for marijuana when they are around secondhand marijuana smoke, but don’t actually take puffs themselves? According to the results of a study that were published last month, the answer is yes. Below is the abstract from the study:


  • Exposure to secondhand cannabis smoke results in absorption of cannabinoids.
  • Secondhand exposure can produce mild subjective and behavioral/cognitive effects.
  • Room ventilation ameliorates the effects of secondhand cannabis smoke exposure.



Cannabis is the most widely used illicit drug. Many individuals are incidentally exposed to secondhand cannabis smoke, but little is known about the effects of this exposure. This report examines the physiological, subjective, and behavioral/cognitive effects of secondhand cannabis exposure, and the influence of room ventilation on these effects.


Non-cannabis-using individuals were exposed to secondhand cannabis smoke from six individuals smoking cannabis (11.3% THC) ad libitum in a specially constructed chamber for 1 h. Chamber ventilation was experimentally manipulated so that participants were exposed under unventilated conditions or with ventilation at a rate of 11 air exchanges/h. Physiological, subjective and behavioral/cognitive measures of cannabis exposure assessed after exposure sessions were compared to baseline measures.


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). One urine specimen tested positive at using a 50 ng/ml cut-off and several specimens were positive at 20 ng/ml. Exposure under ventilated conditions resulted in much lower blood cannabinoid levels, and did not produce sedative drug effects, impairments in performance, or positive urine screen results.


Room ventilation has a pronounced effect on exposure to secondhand cannabis smoke. Under extreme, unventilated conditions, secondhand cannabis smoke exposure can produce detectable levels of THC in blood and urine, minor physiological and subjective drug effects, and minor impairment on a task requiring psychomotor ability and working memory.

So according to researchers, yes you can fail a drug test for being around secondhand marijuana smoke. With the case of NFL player Josh Gordon, he tested positive for 16 ng/ml of THC, which was above the 15 ng/ml threshold that the NFL considers to be a failed test. In his appeal he stated that he was just around other people that were smoking marijuana, and based off of this study, I would be inclined to believe him.

So can people get high from being around secondhand marijuana smoke? It’s a subjective question, but yes, I suppose someone could, especially if they had a very low tolerance. If someone is sitting across the room while someone else is on the other side of the room blowing pipe hits out the window in a well ventilated area, then I would probably say no. But if people are sitting in a cramped space, hotboxing like crazy, then I think it’s definitely possible. Especially if the hotbox session includes joints and blunts, where the smoke billows out of the joint/blunt and isn’t the exhale of the hotbox participants. You have to assume that the smoke can accumulate, and even though a person may be in the session area but isn’t puffing, they are going to inhale that ‘non-lung filtered’ smoke.

Moral of the story is, if you are in a position to where you know you are going to have to submit to a drug test in the near future, it’s best to stay upwind of any marijuana smoke. Also, if you don’t want to get high from secondhand marijuana smoke, you probably shouldn’t volunteer to sit in a confined space with poor ventilation while others are puffing away. Do you have any secondhand marijuana smoke stories? They could be personal, or just a story that you heard. If so, make sure to post them in the comments.

If you have any questions about drug testing, email drugtest@theweedblog.com.


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  • Trevor

    I live in Cali and we are about to legalize weed in November. Since we are a crazy lawsuit state, If I failed a drug test for work or was driving( I have a DUI) and they wanted a blood test can I sue the state or a company that allows smoking in public places or a outdoor patio area( some outdoor bars allow cigarette smoking)?

    Say if I sit down for a coffee at an outdoor cafe inside the restaurant and someone smokes weed on the other side of the fence in a public area.

    My work has a smoking are just outside of the door I work from, over a day I get high (if I metabolize slowly) and sue my work?

  • CS

    Its quite obvious that everybody’s body metabolizes differently.
    Its the same for prescription drugs. What works for someone might not work on someone else.
    Bottom line is, If you can lose your job for testing positive and you “cant afford to lose your job” Make the smart choice and stay away from it. Or get a different job. The choice is up to you.

  • Anonymous

    Help someone, with answers

  • DS

    I have drug test in few days, friend smoked in the house, central air, ceiling fan off, didn’t blow the smoke my way, but can still smell it. I did not inhale at all, smoke was blown away from me. Will I fail a pee test

  • B.S

    oh I ment on my son. sorry I’m German and only trying to write in English

  • B.S

    I have had it up to my head.I want to do a drug test on .your 5year old son. He’s daddy smoked weed and he really behaves funny and coughs always when he comes back to me. He also applied for custody for our son. I need this test so badly.Trying to find out where I can do it in Berlin.

  • Chuck

    I’d like to know if there was burning marijuana in the room when being tested (breathing in the smoke first hand) or were they subjected to the exhaled smoke only (second hand smoke)

  • Nat

    Never smoked in my life but was with some friends that’s smoked last night(Saturday). I forgot I had a drug test in the morning (not the following tomorrow (Monday). I’ve heard weight, diet, and exercise affect it also-so I’m a 120 lb 5’6 lean runner who drinks plenty of water and clearly exercises regularly. I’ll update this post once I get the results back.

  • Erik

    I failed mine guys, ive been smoking fir years, had a number of negative tests for weed results back to back, after one smoke session, which i took no part of, the second hand smoke made me dirty. The oral tests go as low as 12ngl. Be careful guys, the uas only go to about thirty, so if you havent smoke your ngl can be about 15 to 20, youcan see this is an issue. Took an additional tests just in case after the oral test and was negative. Thank god

  • Non Smoker

    I sat in living room with people smoking pot I do not smoke anything or drink ,they did not have central air just window unit was there about 3 hours watched a movie they smoked 3 joints during that time ,1 month later I failed drug test my doctor said you can’t get from second hand smoke ,now thanks I smoke ,It was a family member I only get to see 1 time a month as I live 320 miles away so now I can’t go see them at there house anymore.So for people that say you can’t fail test from second hand smoke if don’t have central air or windows open ,you can and will fail

  • Breann Nelson

    I had a saliva test done to me for a job. I smoked the entire day before and all I did was brushed my teeth in the morning and rinsed with Listerine and my test came out negative and I got the job.

  • Carrie

    I am not a smoker but my husband is, hr smokes in the house daily. I just failed a saliva test and haven’t actually used in YEARS.

  • Kitty3055

    I have a saliva drug test tommorrow I did a little hit of weed out of a bong on wenesday night around 11 or so 5 days passed already and I have a drug test tommorrow I been eating ice peeing a lot and using golden seal and water and brushing my teeth and using lesterine I wanna know if there’s any chance of me passing this saliva drug test I can’t afford to lose my job Any ones opinion is helpful at this point

  • Ralph

    I honestly Bro you are hard on this guy a little he doesn’t know that’s why he is asking , and I’m sure things get very difficult when you have family trying to support at this hard times we are all brothers just try to look after eachother I really didn’t know too That too I Thank you for clearing this up I know who to ask next time though.. LOL.

  • ASU1389

    Yeah if your in the world of jobbers maybe. Professionals with college degrees generally don’t. I’m 29 and have never had the humiliation of submitting my urine for testing. But good luck steering clear of random pot clouds getting you high!
    And I’m stupid???

  • Philip VanDoren

    Youre both dumb as shit. If I was 15 how could I have quit decades ago. Also I guess you’ve never seen smoke blow down along the ground. Gravity doesn’t make things rise it effects objects based on mass. Smoke rises because it is hotter than the air around it. Get off the dope, get an education. All jobs in my state require a UA unless you’re making minimum wage and BTW dipshit most places these days will just swab your mouth and get an instant result.

  • ASU1389

    Your an idiot and that child is right. And if smoke rises how would it make it 30 yards to you thick enough to get you high. The study says this is only true in extreme conditions… Being outside and smelling it and getting the placebo is totally different… It’s cool bud we were all 15 at one point. Good luck with your job. Better yet go to college and get some real skills and a job that doesn’t require a Ua.

  • Philip VanDoren

    “Smoke rises due to the laws of gravity” and you have the nerve to call me stupid. Sit the fuck down child.