Scaled cannabinoid hemp extraction has largely pursued a cold ethanol process.  CO₂ is also widely used in circumstances where throughput is not the primary concern and allows operators to avoid using explosive solvents.  The solvents from hydrocarbon extraction processes present an increased risk for lung or cardiovascular damage, and these dangerous solvents helped to drive the popularity of CO2 as a safer alternative. Butane Hash Oil (BHO) is widely consumed by cannabis users, and remains very popular in dispensaries, along with solventless extracts like live rosin.  BHO is estimated to comprise well over half of the concentrates on dispensary shelves, some estimates say over 75%.   

Residual solvents have historically been addressed with vacuum purging, and these processes have been refined over time by modifying parameters to produce products with 0% residual solvent.  The high THC segment, broadly…