Cannabinoids, to include THC, are extracted from marijuana plant material in a variety of ways. The majority of the cannabinoids are found in the oily resin on the outside of the cannabis plant. One of the most common and most dangerous methods of extraction involves the use of butane, a solvent that dissolves the cannabinoids, allowing them to separate from the other plant material. Other solvents, like Freon, hexane, isopropyl alcohol, and ethanol, are also used. Carbon dioxide extraction, also known as supercritical fluid extraction, uses high pressure to separate the cannabinoids from the plant material. The ice-water filtration method uses ice or dry-ice for this separation: the cold temperatures make the resin brittle enough to break away from the plant material. The “rosin technique” extracts cannabinoids using heated pressure, often from a flat-iron, heated spoon, or a commercial heat-press made for producing marijuana concentrates.