Ask Our Experts: THC Limits for Hemp


Q: I hear contradictory things about the acceptable THC threshold for hemp; what is the limit, and does it change by state?

By New Frontier Data

A: Ever since the USDA released its interim final rule for the federal domestic hemp program, there has been confusion regarding the legal limit for THC. While the legal limit for THC in hemp plants is 0.3%, the key is how it is measured.

Typically, most states measured delta-9 THC when checking a hemp plant’s THC concentration. Under the new USDA rule, however, testing labs must check for total THC content, including THCA (a nonpsychoactive acid form of THC found in raw hemp plants). THCA can be converted to THC through the decarboxylation process.

Standards get increasingly muddled between state policies. The 2014 Farm Bill allowed states to create hemp research pilot programs, many of which were more permissive in testing than is the current USDA standard. Under the latest USDA rules, states that took advantage of the 2014 Farm Bill may for now keep their hemp research pilot programs and forgo the USDA standard.

States that have chosen to adhere to the 2014 Farm Bill may have different testing regulations than those having adopted USDA-approved plans. Colorado, for example, will only be testing for delta-9 THC, and not THCA. Consequently, a hemp plant grown in Colorado may not necessarily be legal in Delaware.

The USDA keeps a list of states with USDA-approved plans versus those choosing to observe the 2014 Farm Bill. When dealing with interstate hemp transportation, it is vital to consider the variations in order to navigate the legal landscape and save both time and money.