Only under hot box conditions for at least an hour according to a three part study conducted by researchers at John Hopkins University School of Medicine.
In this series of studies, cannabis smokers and non-smokers were placed in either a ventillated or non-ventillated room to assess if second-hand smoke causes intoxication in non-smokers. They found that "passive non-smokers can become legally intoxicated with slight subjective impairment in extreme conditions, such as a small, unventillated room, where a large amount of cannabis is being burned in close proximity to the non-smokers".
-Cone (2015) Study III of III
Cone (2014) Study 1. Figure 2.
Each study was a "session". That's right, a good 'ol pass-the-joint group sesh. The conditions of the sessions were as follows:
<5% THC (of a smoker's dose) delivered to non-smokers
6-18% THC (of smoker's dose) delievered to non-smokers
<5% THC (of smoker's dose) delivered to non-smokers
Two factors affected intoxication of non-smokers: quantity of cannabis burning and room size/ventilation.
The results demonstrated that extreme cannabis smoke exposure can produce positive urine tests at commonly utilized cutoff concentrations, aka "legally intoxicated". However, positive tests are likely to be rare, limited to the hours immediately post-exposure, and occur only under environmental circumstances where exposure is obvious." See Study 1, figure 3.
-Cone (2014) Study I of III
"During Sessions 1 and 2 (unventilated conditions), there was rapid accumulation of smoke inside the chamber that persisted throughout the 1-h period, whereas in Session 3 (ventilated condition), visible smoke was present, but at lower levels".
Room size and 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. 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.
-Hermann (2015) Study II of III
So, if you're worried that you might get high, don't hang out in small, unventilated rooms which are obviously visibly filled with smoke. Remember, the bigger and more ventilated the space, the less contact of second-hand smoke. Vaporizing is a good way to eliminate smoke production; vapour in a ventillated room does not produce second-hand exposure. A 2018 study showed that there was no second-hand exposure to staff administering vaporised cannabinoid products to patients in a hospital setting.
💨💨💨💨💨💨Sources:💨💨💨💨💨💨
Cone EJ, et al (2014). "Non-smoker exposure to secondhand cannabis smoke. I. Urine screening and confirmation results". Journal Analalytic Toxicology. Vol 39 (1), pp. 1-12. doi: 10.1093/jat/bku116. https://www.ncbi.nlm.nih.gov/pubmed/25326203
Herrmann ES, et al (2015). "Non-smoker exposure to secondhand cannabis smoke II: Effect of room ventilation on the physiological, subjective, and behavioral/cognitive effects". Drug Alcohol Dependence. Vol 1 (isue 151), pp. 194-202. doi: 10.1016/j.drugalcdep.2015.03.019. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4747424/ https://www.hopkinsmedicine.org/news/media/releases/extreme_exposure_to_secondhand_cannabis_smoke_causes_mild_intoxication
Cone EJ, et al (2015). "Non-smoker Exposure to Secondhand Cannabis Smoke III. Oral Fluid and Blood Drug Concentrations and Corresponding Subjective Effects". Journal Analytical Toxicolgy. Vol 39(issue 7), pp. 497-509. doi: 10.1093/jat/bkv070. https://www.ncbi.nlm.nih.gov/pubmed/26139312
Solowij N, et al (2018). "Second-Hand Exposure of Staff Administering Vaporised Cannabinoid Products to Patients in a Hospital Setting". Drugs R&D. Vol 18 (1), pp. 41-44. doi: 10.1007/s40268-017-0225-5. https://www.ncbi.nlm.nih.gov/pubmed/29330776
" 'Extreme' Exposure to Secondhand Cannabis Smoke Causes Mild Intoxication" John Hopkins Medicine https://www.hopkinsmedicine.org/news/media/releases/extreme_exposure_to_secondhand_cannabis_smoke_causes_mild_intoxication
When you're smoking or even vaping somewhere as ventilated as this, some stupid prude will still come along and pretend that they're getting intoxicated off second-hand smoke which couldn't possibly physically reach them. We need to remind those people that they're experiencing a placebo effect from a scent they've been conditioned to fear, and we're not blowing smoke up their ass. ;)
