Researchers have identified a complex mixture of chemical compounds produced when THC is exposed to temperatures associated with smoking marijuana, detecting 79 compounds in a new laboratory study published in the Journal of Cannabis Research.
Conducted by researchers at Louisiana State University’s Department of Chemistry, the study examined how delta-9-tetrahydrocannabinol (THC) breaks down when exposed to intense heat.
Researchers heated purified THC samples to temperatures ranging from 400 to 800 degrees Celsius, corresponding to conditions found in the heated zone of a burning cigarette. The resulting chemical mixtures were examined using two-dimensional gas chromatography combined with high-resolution mass spectrometry.
Across the five temperatures examined, researchers detected 79 chemical breakdown products, successfully identifying 75.
The compounds included several classes of chemicals, including aromatic hydrocarbons, cycloalkanes, alkenes, phenols, ketones and other small molecules.
Researchers found that the chemical mixture became increasingly complex as temperatures rose. The greatest number of compounds was detected at 700 degrees Celsius, while the fewest were detected at 400 degrees Celsius.
Of the 75 identified compounds, 34 had previously been detected in marijuana smoke. Researchers said several of these substances have been observed in smoke but not in the marijuana plant itself, suggesting that some may be generated when THC breaks down during combustion.
The researchers also examined existing scientific literature concerning the biological effects of the identified chemicals.
Twenty compounds have previously been associated with adverse biological effects, including genetic damage and nervous system toxicity. Other identified substances have been investigated for potentially beneficial properties, including antimicrobial and anticancer activity.
The findings illustrate how heating THC can produce chemicals that are not necessarily present in the original cannabinoid, significantly changing the chemical composition of material that may subsequently be inhaled.
The experiment used purified THC rather than whole marijuana flower, allowing researchers to isolate compounds originating from THC itself rather than the many other substances naturally present in the plant. The study examined chemical formation and identification, not health outcomes in marijuana consumers.
The research was supported by funding from the National Institute of Justice, part of the U.S. Department of Justice.
