The majority of CBD products for sale on the market today are produced using the CO2 extraction method. This method of extraction produces the cleanest end product because it is able to remove harmful chemicals and heavy metals that may have been stored in the plant due to pesticide treatment or other chemical applications.  It also produces the highest yield and provides the most control over the final product, which appeals to manufacturers for a number of reasons.  This is the only method you can use to remove all the naturally occurring THC in the hemp plant create CBD isolate, and they can even use this process to isolate certain cannabinoids to create full or broad spectrum CBD.