Pyrolysis

Pyrolysis is the chemical decomposition that occurs when cannabis is burned. Combustion temperatures (~800°C) decarboxylate THCA into Delta-9 THC and also create unwanted byproducts like benzene and acetaldehyde. Vaporization (~200°C) achieves THCA-to-THC conversion without significant pyrolysis byproducts, which is why vaping is generally considered cleaner than smoking.

Example: Vaping at 200°C avoids the pyrolysis byproducts you get from a lighter.

Etymology: From Greek 'pyr' (fire) + 'lysis' (separation).