A recent study done by Johns Hopkins University School of Medicine, published in the journal Drug and Alcohol Dependence, concluded that secondhand pot smoke can intoxicate nonsmokers under “extreme conditions,” like being in an unventilated room or closed vehicle.

Researchers recruited pot smokers and non-smokers who sat together for an hour, side-by-side, in a 10-by-13-foot hot box – an acrylic-walled chamber, with the smokers toking on 10 strong joints, reported Science Daily. The exact same situation was carried out in a ventilated room with fans.

At the end of the exposures, the participants’ blood, urine, saliva and hair were tested for THC. All six nonsmokers who’d been in the hot box had detectable amounts of THC in their urine and blood, one of whom tested with the same cutoff (50 nanograms per milliliter) used in the Federal Workplace Drug Testing Program. They also reported feeling pleasant, tired, and less alert… in other words—stoned.

Non-smokers who sat in the ventilated chamber with the smokers showed no signs of THC in their systems. The only effect they reported was being hungry!

When the nonsmokers were asked to duplicate grid patterns they saw on a computer monitor or perform a basic numbers drill, the ones who sat in the unventilated room responded faster but made more mistakes.

“The behavioral and cognitive effects were minor and consistent with a mild cannabis effect,” said lead author Evan S. Herrmann, Ph.D.

This was the first comprehensive study on secondhand pot smoke since the 1980s. In that pot potency has tripled in recent years, research obviously needed to be updated.

Oh, in case you were wondering, the weed used in the experiment was provided by the National Institute on Drug Abuse.