CBD oil is made from hemp - better organic hemp.
The aromas are obtained from the flowers using a steam distillation process. In order for the hemp flower to become a CBD oil, CO2 extraction follows. Now you finally have a cleaned CBD paste that is rich in cannabinoids.
What happens to the CBD paste?
After the extraction process of the CBD paste you can do that add more flavors to future CBD oil and choose a carrier oil. When the CBD oil has been made from the CBD paste, you can still run it through various filter processes. After filtering the CBD oil you have a product that is free of by-products such as waxes, fats and chlorophyll!
How is the THC removed?
In the EU, CBD oils are allowed - and all other CBD products - contain no more than 0.2% THC. The CBD oil is freed from THC using the THC HPLC-UV method. Depending on how thoroughly the process is implemented, (almost) no more THC values are left in the CBD oil. However, since you cannot guarantee 100% that the THC has been completely filtered out of the CBD oil, you rarely see - if not - products that describe the THC value with 0%.