Does Secondhand Weed Smoke Exist?

Cannabis is becoming increasingly legal, and while usage rates have not changed much, pot smoking is often much more open than it was just a short time ago. This has a lot of people wondering, does secondhand weed smoke exist?

The simple answer is “yes”, but there’s more to it than that. 

Can Secondhand Weed Smoke Get You High?

There have been several studies to address this question, and while popular culture likes to joke about the supposed “contact high”, it turns out that secondhand weed smoke does not get you stoned. 

But the situation isn’t as simple is this would make it seem. 

Can Secondhand Weed Smoke Make You Fail a Drug Test?

Further studies have concluded that secondhand marijuana smoke can end up in your system, and it can be enough to make you fail a drug test. 

In a study at John Hopkins University, research subjects who had never smoked weed were put in a sealed chamber with no ventilation, then surrounded by smokers who were puffing away at cannabis of different strengths. Afterwards, the non-smokers went through a series of urine tests. Not only was THC found in each of their urine, but each hit amounts of 20 ng/mL, which is the threshold for workplace drug testing. Their THC levels remained at this point for up to 22 hours.

Does Secondhand Weed Smoke Exist?

It’s worth pointing out that the threshold mentioned is generally for existing employees. Preliminary drug tests for new hires tends to have a much higher threshold of 50 ng/mL. 

It’s also important to mention that the test subjects were all kept in sealed rooms, and that the vast majority of smoking does not occur under these circumstances. 

So should you be worried about failing a drug test after hanging around tokers? Probably not, unless you’ve spent prolonged periods of time in an airtight space.