The U.S. 1970 Controlled Substances Act (CSA) made cannabis effectively illegal, especially the resinous parts of the plants. However, it also asserts that certain parts of the mature stalk or sterilized seed is exempt from this classification. The flowers, the leaves, and the sticky resin were not included in this exemption. The resin and its derivatives were explicitly forbidden wherever they are found on the plant.
The resin is the most important part of cannabis when it comes to medicine. Found in trichomes, the gooey, sticky resin contains THC (tetrahydrocannabinol) and CBD (cannabidiol). It should also be noted that hemp oil is not the same as CBD-rich resin extracted from the flowers and buds of cannabis. Hemp oil contains no CBD, THC, or cannabinoids but is used in the making products such as paint, soap, food supplements, and more.
The FDA credits cannabis resin as the key factor between industrial hemp and marijuana. Yet similar to how operating a vehicle under the legal limit of the consumption of alcohol is legal, so is the characterization of industrial hemp since it houses no more than 0.3% of THC. These low levels of THC produce no intoxicating effects during consumption. Thus cannabis is considered hemp, and not marijuana, if no part of the plant contains a THC concentration of under 0.3%.
The Agricultural Act of 2014, sometimes referred to as the Farm Bill, stated for the first time in U.S. history that industrial hemp does not classify legally as marijuana. This decision of the 0.3 percent threshold was also confirmed again when Congress re-approved the Farm Bill again in 2018.
However, there was no mention of resin in the 2018 Farm Bill, which still features backwards, outdated thinking on THC limits. The number is arbitrary, lacks a scientific basis, and continuously keeps patients from accessing alternative therapeutic and medicinal options using both CBD and THC.
The Farm Bill of 2018 effectively removed hemp products, including hemp-derived CBD from the list of controlled substances. The CSA no longer considerers these products under it's purview however the FDA (Food and Drug Administration) does not recognize hemp-derived CBD as approved medication or food.
Still, there is more CBD resin found in organically grown cannabis than industrial hemp as industrial hemp contains far less cannabidoil than CBD -rich cannabis. Thus, large amounts of hemp is needed to extract small amounts of CBD and incurs additional risk of plant toxins and other bio-matters. Alternatively, some hemp production involves the re-sale of leftovers for CBD extraction. This process is highly unregulated and usually results in heavily tainted and often toxic CBD products. Low-resin hemp also also more prone to mold and pest infestation.
Before the Farm Bill of 2018 many CBD products were produced from low-resin industrial hemp grown in China. Yet, now that hemp is legal in the United States, it is easier to obtain higher quality CBD products from hemp grown in Colorado, California, Vermont, Montana, Oregon, and other U.S. states. With present-day horticultury, America has been able to begin scientifically breeding new strains of high-resin hemp that satisfies the Farm Bill's criteria for hemp related plants while measuring below 0.3 percent THC. Alternatively, we've been able to grow high-resin cannabis with less that 0.3 THC as well, thus qualifying for legal consumption, throughout America.