Hemp-CBD: USDA Reopens Commenting for 30 Days on Interim Hemp Rule

usda hemp cbd testing

usda hemp cbd testing

Everyone in the hemp industry knows that last fall the U.S. Department of Agriculture (“USDA”) released its interim hemp rules governing the production of hemp. Our hemp-CBD attorneys have written extensively about the new hemp rules and their shortcomings, as well as the panoply of different hemp regulations at the state level and the DEA’s recent promulgation of an interim rule that may criminalize the processing of hemp:

Next week, on September 17, three of our attorneys (Nathalie Bougenies, Daniel Shortt, and Griffen Thorne) are leading a free Q &A webinar on all aspects on hemp and CBD. Here’s a link for more information on the webinar and how to register.

The timing of the webinar couldn’t be better as the USDA just announced that it is reopening the comment period on the hemp rules for 30 days. The comment period opened yesterday, September 8, and all comments must be received by October 8, 2020. The reopening is notable because the USDA received over 4,600 comments during the initial 90-day period.

As explained in the notice of reopening, the USDA is particularly interested in comments on the following topics:

  • Measurement of Uncertainty for Sampling
  • Liquid Chromatography Factor, 0.877
  • Disposal and Remediation of Non-Compliant Plants
  • Negligence
  • Interstate Commerce
  • 15-day Harvest Window
  • Hemp seedlings, microgreens, and clones
  • Hemp breeding and research
  • Sampling Methodology – Flower vs. Whole Plant
  • Sampling Methodology – Homogenous Composition, Frequency, and Volume
  • Sampling Agents
  • DEA Laboratory Registration

Today I’ll discuss one of these topics and why it matters.

Liquid Chromatography Factor, 0.877

This topic goes to the requirement that all hemp be tested for “total THC.” As Nathalie Bougenies has explained, total THC is the molar sum of delta-9 THC (“THC”) and delta-9 tetrahydrocannabinolic acid (“THCA”). The 2018 Farm Bill requires that all testing for THC levels use postdecarboxylation or similar methods. Cannabis plants with total THC levels higher than .3%, plus a measurement of uncertainty, are classified as marijuana and deemed a Schedule I controlled substance.

The two accepted methods for measuring cannabinoids in industrial hemp are gas chromatography (“GC”) and high-pressure liquid chromatography (“HPLC”). HPLC uses a pump to push liquid solutions through a column at high pressure to separate chemicals. The process does not utilize heat and so cannabinoids do not undergo decarboxylation and so remain in their original form. In layperson’s terms this means that HPLC does not convert THCA into delta-9 THC (unlike GC, which uses heat and transforms the acid cannabinoids, e.g. THCA, into their neutral form, e.g. THC). So test results using HPLC show concentrations for cannabinoids in both their acidic and neutral form.

When using HPLC, the total THC is determined by summing the delta-9 THC and the THCA concentrations. Currently, the THCA concentration is multiplied by correction factor of .877 to account for the weight of the carboxylic acid chain on TCHA. (If this sounds like we are weighing a chain of atoms on a molecule to determine whether a cannabis plant is hemp or marijuana, we are).

In its call for comments on this topic, the USDA states:

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.

These commenters call for alternative methods, including one that would multiply the THCA content by .5262 instead of .877. So proponents of lowering the correction factor from .877 seek to take into account both (1) the weight of the carboxylic acid on the TCHA molecule, and (2) that the conversion of THCA into delta-9 THC is never perfect. Whether the correction factor ought to be .5262 or some other number is beyond me— I’ll leave the science to the scientists. But just playing around with the following equation demonstrates why this is important: % Total THC = % THC + (% THCA x Correction Factor). Plainly, a correction factor of .877 results in a higher Total THC than a correction factor of .5262.

So how the USDA resolves this one issue will have significant consequences for whether any given batch of cannabis is hemp or (federally) illegal marijuana.

If you have the scientific expertise to comment on the correction factor, I encourage you to do so. I encourage everyone in the hemp CBD space to comment on what aspect of the interim hemp rules matters most to them. Written comments should be submitted via the Federal eRulemaking portal at www.regulations.gov. Comments may also be sent via email to [email protected] or sent by postal mail to USDA/AMS/Specialty Crops Program Hemp Branch, 470 L’Enfant Plaza SW, PO Box 23192, Washington DC 20026.

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