Cannabinoid boiling point misinformation explained

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Delta-9 tetrahydrocannabinol (THC) was first isolated from cannabis plants with its boiling point documented in 1964 in Israel. That discovery was made 22 years after the first extraction of THC isomers. Before then, or even Roger Adams’ discovery of CBD in 1940, though, a compound with a similar boiling point as THC was noted in cannabis oil provided by Merck at the time. Oddly then, a deep well of misinformation surrounds cannabinoid boiling points in publications today.

CBN found in 1800s cannabis oil by Merck

Chemists found a new compound in hashish in 1896, later isolated by R.S. Cahn in the 1930s. The molecule turned out to be (allegedly) cannabinol (CBN), the first cannabinoid discovered. And while the compound discovered in 1896 might have contained THC, it means that a boiling point lead to the elucidation of cannabinoids nearly a century ago. Regardless, cannabinoid boiling points are riddled with misinformation today.

The temperature at which THC boils has been accurately reiterated by leading chemists in recent years. Two examples are Dr. Mark Scialdone, and separately, Dr. Markus Roggen of Delic Labs. Both chemists have laminated the correct cannabinoid boiling points on various platforms. Scialdone has discussed in length the discoveries made in 1896.

Yet common information shared on the Web and Social Media incorrectly depicts the boiling points of CBN as 185° and THC as 156° degrees Celsius.

Cannabinoid boiling points without known misinformation.
CBG melts at 52°C, but somehow, that temperature has been incorrectly used as its boiling point across digital platforms.

Boiling points in a deep vacuum

If you were told vape pens boil CBN at 185 degrees Celsius (365°F), perhaps the communication came from outer space. While water does boil at room temperature and CBN boils at 185°C under a deep vacuum. Cannabinoids boil at much higher temperatures on Earth’s surface, where consumers toke up.

CBN and THC both boil above 400° Celcius at pressures found on the planet’s surface. Creating misinformation, the temperatures that cannabinoids boil at under a full vacuum are often used to depict regular boiling points, too. To clear the confusion, an equation is used to adjust boiling points at different atmospheric pressures.

Let us if you know in the comments if you were familiar with the true temperature that cannabinoids boil. And check out this story to read how THC aerosolizes rather than boils in a vape pen.

Note — This report has been updated on April 3, 2022, following a video call with Dr. Mark Scialdone to include the possibility that the “red oil’ obtained by Woods et al. contained THC as opposed to pure CBN.

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  • Cannabinoids only boil between ~150 to 220° Celcius in a special laboratory setting whereby the atmospheric pressure has been mechanically reduced to nearly zero.
  • Woods et al. used atmospheres of 20mm, 46mm, and 100m and respective temperatures of 265°, 300°, and 315° Celcius to boil the cannabinoid they coined CBN.
  • Under normal atmospheric conditions, cannabinoids boil between ~400 to 500 degrees Celcius.
  • The boiling point of CBG is only known based on predicted values calculated using a mathematical equation, it is not yet known based on direct experimental data.

Source

  1. Gaoni Y, Mechoulam R. Isolation, structure, and partial synthesis of an active constituent of hashish. J Am Chem Soc. 1964;86(8):1646-1647.
  2. Pertwee R. G. (2006). Cannabinoid pharmacology: the first 66 years. British journal of pharmacology, 147 Suppl 1(Suppl 1), S163–S171.
  3. Wood TB, Spivey WTN, Easterfield TH. Xl. —charas. The resin of indian hemp. J Chem Soc, Trans. 1896;69(0):539-546.
  4. Lovestead, T. M., & Bruno, T. J. (2017). Determination of Cannabinoid Vapor Pressures to Aid in Vapor Phase Detection of Intoxication. Forensic chemistry (Amsterdam, Netherlands), 5, 79–85.

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