From New Chapter's Supercritical Extraction Process
Supercritical (CO2) Extraction is a method that not only provides for a more potent supplement, but also does so in a manner that may be "greener". In addition, it provides for a cleaner product with less contaminants.
"The supercritical process is extraordinarily complex and high-tech, but at its core we think it is rather easy to understand. Here is a short “botany” lesson: there are two major groupings of phytochemicals, or plant constituents, that are generally extracted. One type of plant constituent “likes” water, and is thus willing to be dissolved in water (like in making a tea, which is simply a hot water extract) or a related solution like ethanol. The other type of plant constituent “dislikes” water, avoids it totally (like oil and water!), and is thus unwilling to be dissolved in it. These water-avoiding constituents are fatty or oily in nature, and they are willing to dissolve only in “lipophilic” or fat-loving solutions. To extract an “oily” constituent, people conventionally either dissolved the herb in a chemical solvent or heated the herb to beyond boiling, evaporating out the water-based ingredients. That is the sum and substance of conventional extraction: a water-loving constituent either can be dissolved in a water or alcohol solution, or it is fatty or oily and needs to be dissolved in a different manner. We should note that some lipophilic substances can be extracted with ethanol, but it is not the preferred extraction method for those substances.
... all that is left behind is the pure, concentrated extract. No pollution, no heat stress or damage, and no solvent residue. The extract, if done by a fine laboratory or facility, can be a broad, virtually complete representation of the plant’s lipophilic constituents.
"Recent studies have proved SC-CO2 is an effective alternative for terminal sterilization of biological materials and medical devices. Moreover, this process is gentle; as the morphology, ultrastructure, and protein profiles of inactivated microbes are maintained."
"Detailed GC-MS analysis of the products was performed to assess the best extraction and the best separation conditions. The lavender oil produced by supercritical extraction was compared to the oil obtained by hydrodistillation. The major difference between the two products were reflected in linalyl acetate content. The compound was found to be 34.7% of the oil produced by supercritical fluid extraction and 12.1% of the hydrodistilled product."
"Supercritical carbon dioxide is seen as a promising green solvent because it is non-toxic, and a byproduct of other industrial processes. Furthermore, separation of the reaction components from the starting material is much simpler than with traditional organic solvents."
Companies claiming to use Supercritical Extraction
Tattva's Herbs Organics
Wikipedia Entry: Supercritical Carbon Dioxide
Supercritical CO2 Extraction and Fractionation of Lavender Essential Oil and Waxes
 New Chapter: Supercritical Extraction