THC-O is created by converting CBD to either delta 9 THC or delta 8 THC, and then converting these cannabinoids to their acetate form, which is called THC-O for short. The studies cited in the note at the top of this article show that when enough heat is applied to THC-O, the thermal degradation can cause the formation of a dangerous lung toxicant called ketane.
Ketane is a substance used to measure how easily a diesel fuel ignites. Essentially, the higher the cetane number, the faster the fuel ignites.
The risk is not caused by the cannabis itself or vaping, but by the interaction of heat with the acetate form of several chemicals, including THC. In fact, any acetate subjected to heat could produce ketane.
It is not certain whether the amount of ketane produced by a vape is enough to pose an immediate danger to the user, but it is possible. It is also possible to cause cumulative damage to the lungs from repeated small exposures.
In America, THC-O is one of the few alternative cannabinoids deemed illegal under federal law.
