Wikipedia can be a great source of information, but don’t always trust it. When it comes to numerical values, like the boiling point of a compound, normally Wikipedia gets close enough because something so simple is easy to agree on, and all the primary sources will provide roughly the same value. But what if we’re dealing with a chemical that has been illegal under federal law since 1937?
“I have seen conflicting reports about the vaporization point of THC,” says Dale Gieringer, PhD. Specifically, the Wikipedia page for THC says the boiling point for THC is 315 °F, and cites this article called Cannabis and Cannabis Extracts: Greater than the Sum of Their Parts? by John M. McPartland and Ethan B. Russo as a source for that number. That article includes a table with the boiling points of seven cannabinoids and cites three different primary sources for those values.
On the one hand you might think the boiling point of THC is 315 °F, but other sources list a different value. Pubchem, an online database of chemical compounds lists the boiling point of THC as 392 °F at 0.02 mm of Hg (a low pressure). Pubchem cites the National Toxicology Program (NTP) as their source. Looking deeper, we see on page 13 of the NTP’s report on THC lists the boiling point as 200 °C, or 392 °F. There’s one catch to this number though, it’s listed as the boiling point of THC at 0.02 mm Hg, meaning 392 °F is the boiling point of THC under a pressure that’s almost a vacuum.
Here’s a quick reminder from high school chemistry class: boiling points are always lower at lower pressures. According to an article by Dale Gieringer called Marijuana Water Pipe and Vaporizer Study, “the vaporization point at normal atmospheric pressure appears to be unknown, but is thought to be in the range 250-400º.”
So where lies the final verdict on the boiling point (a.k.a. vaporization point) of THC? We don’t know, but it’s definitely higher than 315 °F, and probably ever higher than 392 °F. This isn’t to say that cannabinoids won’t start to vaporize at temperatures as low as 300 °F, but other factors are at play in this scenario. Some people may prefer the taste and milder experience of low-temp vaporizing and low-temp dabbing, but those who want a higher yield on their product should definitely aim for a higher temperature.