PHO or as it is also referred to as Propane Hash OIl is more potent than smoking the cannabis bud. due to the concentration factor. PHO involves the use of solvents for production. The cannabis bud is added to the propane to extract the cannabinoids and terpenes. This process makes the PHO product about 80% stronger than the bud. Novice users should stay clear of Proper PHO Shatter.