USDA Reopens Comment Period on Hemp Interim Final Rule: Opportunity to Provide Feedback

— Written By

9/5/2020 – The USDA published its Interim Final Rule (IFR) in October 2019. There were a number of items in the IFR that were of concern for growers and others in the industry.

The USDA has reopened the comment period on the IFR. This is an opportunity to address specific issues that were raised by the public during the first open comment period, before the final rule is published. The USDA is looking for feedback on specific items, some of which are noted below.

*Important: the comment period is only open until October 8, 2020. Comments should be submitted via the Federal eRulemaking portal. Comments may also be sent via electronic mail to All comments should reference the document number (2020-17659) and the date (September 8, 2020) and page number (55363-55366) of this issue of the Federal Register and will be made available for public inspection in the Office of the Docket Clerk during regular business hours, or can be viewed at: Federal eRulemaking portal

Items of note are listed below, with excerpts of language taken directly from USDA’s announcement in the Federal Register:

Measurement of Uncertainty for Sampling

The IFR addresses the measurement of uncertainty (MU) in laboratory activities by requiring labs to report the MU as part of any hemp test results. However, the IFR does not address or provide an MU to account for the variability that may occur prior to a sample arriving at a laboratory during cutting, bagging, sealing, transporting, handling, and other “pre-laboratory” activities. Multiple commenters suggested the establishment of an additional MU to account for this variability in addition to the MU provided in the IFR applicable to “in-laboratory” activities. Commenters said that sampling uncertainty arises from the processes related to the collection and handling of the actual plant material to be tested, and the omission of sampling uncertainty in the MU will certainly result in inaccurate, incomplete, and otherwise invalid test results due to the nature of the hemp sampling. One potential way to address this, as presented in a comment, would add an additional MU for pre-laboratory activities (a), in addition to the measurement of uncertainty for in-laboratory activities (b), such that a total measurement of uncertainty (c) can be calculated as the square root of the sum of those squared values (a squared plus b squared = c squared). For example, if the in-laboratory measurement of uncertainty (b) is calculated as 0.0300 percent, and the pre-laboratory measurement of uncertainty (a) is estimated to be 0.0400 percent, then the total measurement of uncertainty (c) would be 0.0500 percent. AMS seeks additional information on this topic and alternative proposals on how to compute the MU for sampling. Numerical valuations or calculation formulas submitted with comments should clearly demonstrate how sampling uncertainty might be incorporated into the current THC tolerance threshold established by the IFR.

Liquid Chromatography Factor, 0.877

The 2018 Farm Bill mandates that all cannabis be tested for THC concentration levels using ‘‘postdecarboxylation’’ or similar methods. As explained in the IFR, ‘‘postdecarboxylation’’ means testing methodologies for THC concentration levels in hemp, where the total potential delta-9-tetrahydrocannabinol content, derived from the sum of the THC and THCA content, is determined and reported on a dry weight basis. The postdecarboxylation value of THC can be calculated by using a chromatograph technique using heat, known as gas chromatography, through which THCA is converted from its acid form to its neutral form, THC. The result of this test calculates total potential THC. The postdecarboxylation value of THC can also be calculated by using a high-performance liquid chromatograph technique (“LC or “HPLC”), which keeps the THCA intact, and requires a conversion calculation of THCA to calculate total potential THC. As explained in the IFR, the decarboxylated value is calculated using a conversion formula that sums delta-9 THC (Δ9-THC) and (87.7) percent of THC-A. Several commenters claim that this formula is inaccurate since it is based on a 100 percent conversion factor, which is nearly impossible to achieve in a laboratory setting. In other words, commenters claim that since the conversion of the THCA to Δ9-THC is never perfectly complete without loss or degradation of starting material, the molar sum of Δ9-THC and THCA-A measured by LC is always higher than the total Δ9-THC measured by GC. To account for this, commenters presented several alternative computation methods, one of which would not multiply the THCA content by 87.7 percent, but rather by 52.62 percent, which is 60 percent of 87.7 percent. Based on comments questioning the accuracy of this figure, AMS seeks additional information from stakeholders regarding the use of this conversion formula. Any alternative factors provided should be clearly quantified and explained.


Commenters to the IFR suggested AMS increase the negligence threshold from 0.5 percent to 1.0 percent. AMS seeks additional stakeholder comments specific to this suggestion. Comments should include quantitative and qualitative data if available.

Interstate commerce

The 2018 Farm Bill and IFR indicate that no State or Indian Tribe may prohibit the transportation or shipment of legally produced hemp across State or Tribal boundaries. Based on comments to the IFR, we are seeking additional input on whether the IFR is sufficient, or if additional regulatory requirements are needed, to facilitate domestic interstate commerce and transactions, particularly the potential need for national, comprehensive, documentation requirements. Commenters presented several proposals on the kinds of documentation that should be required to accompany raw hemp during transport from a farm to a processing and/or a drying facility. For example, commenters suggested that producers be required to include certain documentation such as copies of the laboratory testing report(s), hemp grower license, invoice / bill of lading, and contact information of buyer and seller. AMS is requesting comments on whether documentation of this nature should be required to accompany all shipments of hemp throughout the U.S.

15 day testing window

AMS received a significant number of comments on the 15-day requirement during the initial comment period. Commenters to the IFR suggested AMS increase the 15-day window to 30 days. AMS is seeking additional comments on this suggestion as well as explanations on why a 30-day window may be more appropriate.

Hemp seedlings, microgreens, and clones

Based on comments submitted in response to the IFR, AMS now seeks additional information from stakeholders regarding agricultural operations that grow cannabis plants, but not to maturity, and without mature flowers. These facilities include seedling, seed, clone, microgreen, and other types of operations that do not grow hemp plants for harvesting mature hemp flowers, and are therefore unable to meet the sampling and testing requirements as described in the IFR. AMS is considering the inclusion of specific regulatory provisions to still require licensing but not subject licensees to the same sampling and testing criteria as required of traditional hemp growers that sell mature hemp into the stream of commerce.

Hemp breeding and research

AMS is considering establishing certain regulatory provisions for researchers and research facilities. Specifically, AMS is requesting input on whether employees of research facilities should be required to obtain a license, and whether these types of facilities should have certain disposal protocols for non-compliant plants. AMS is also considering an exemption for researchers and research facilities from the sampling and testing requirements required of traditional hemp growers who sell hemp into the stream of commerce.

Sampling Methodology – Homogenous Composition, Frequency, and Volume

AMS is considering establishing a specific number of plants to be sampled from every lot, regardless of the lot size, and is requesting input on how to establish these requirements. Specifically, AMS is requesting input on how to potentially establish a fixed sliding scale (for example, a lot of fewer than 10 acres requires a sample of five plants; a lot of between 10 and 20 acres requires six plants; etc.,) rather than leaving those calculations to each State and Tribe. AMS is also considering establishment of different sampling and testing requirements for hemp based on end use (i.e. risk-based.) AMS further seeks stakeholder comment on potential risk-based methods for hemp lot sampling for differing varietals intended for fiber, grain, seed, or biomass for extract.

Sampling Agents

The IFR requires that all hemp production must be sampled and tested for THC concentration levels, and that samples must be collected by a USDA-approved sampling agent or a Federal, State, or local law enforcement agent authorized by USDA to collect samples. Currently, sampling agents are required to complete a basic training module offered by AMS. AMS is now soliciting comment on the potential need for more rigorous training and/or certification requirements for sampling agents. For example, AMS is interested in whether sampling agents should be required to complete an online training module administered by AMS and pass an examination. Or, alternatively, whether States and Tribes should be able to develop and require the completion of specific training programs for sampling agents under their respective State or Tribal hemp programs. AMS is specifically requesting input on the content of sampling agent training, the frequency with which training should occur, and whether AMS should maintain a national list of trained sampling agents on the AMS website. The comments should clearly explain why additional requirements may be necessary and suggest what those additional requirements may entail.

DEA Laboratory Registration

AMS is now requesting additional input on whether the DEA laboratory registration requirement should be permanently removed, and if so, how lab disposal requirements of non-compliant hemp samples will adhere to the requirements of the Controlled Substances Act.


The full document can be found in the Federal Register.