CO2s are Essential Oils extracted by Carbon Dioxide (CO2) without the use of heat distillation.  CO2 Essential Oil extraction is a supercritical fluid extraction with natural carbon dioxide, no solvent residues, no inorganic salts, no heavy metals, no reproducible microorganisms 

CO2s are wonderfully rounded, aromatic oils. Some prefer CO2s to steam distilled essential oils, because there is no heat used during the extraction process - only water which then evaporates away, leaving nothing but pure essential oil.