Compliance and testing, in plain English.

What makes hemp "hemp"

Hemp and marijuana are the same plant species. In US federal law the difference is the amount of THC, the compound that causes a high. Under the 2018 Farm Bill, a plant was hemp if it had no more than 0.3% delta-9 THC on a dry-weight basis, meaning measured after the moisture is taken out.

That rule left a gap. Raw hemp contains very little delta-9 THC but can contain a lot of THCA, a related compound that turns into delta-9 THC when it is heated, for example when flower is smoked. A lot could pass the delta-9 test and still behave like marijuana.

Total THC, and how it is calculated

Total THC counts both. Labs report it with this formula:

Total THC = delta-9 THC + (0.877 × THCA)

The 0.877 factor reflects the weight THCA loses when it converts to delta-9 THC. The US Department of Agriculture's hemp testing rules already required this kind of post-decarboxylation result (meaning after heating has converted THCA) for crops tested before harvest. Source: 7 CFR Part 990, USDA Domestic Hemp Production Program (sampling and testing).

The change in late 2026

The federal funding law signed on 12 November 2025 rewrites the definition of hemp. The new definition takes effect 12 months after the law was enacted. In short:

• Total THC replaces delta-9 THC. Hemp must have no more than 0.3% total THC on a dry-weight basis, with THCA counted.
• Finished products face a per-container cap. Final hemp-derived cannabinoid products may contain no more than 0.4 milligrams of total THC per container, meaning the retail package. This applies to consumer products, not to raw bulk flower or biomass traded between businesses.
• Synthetic and converted cannabinoids are excluded. Cannabinoids made in a lab, or chemically converted from CBD, no longer count as hemp.

Our planning dates are 12 November 2026, when the new definition begins to apply, and 11 December 2026, by which we treat every remaining provision as in force. Tillmark does not wait for either: every lot we offer is already reported and judged on total THC.

Sources: Venable LLP, 'Federal Funding Bill Overhauls Hemp Definition, THC Cap' (Nov 2025); JD Supra, 'Congress Narrows Federal Definition of Hemp'; 7 U.S.C. § 1639o (federal hemp definition). This page is a summary for business readers, not legal advice. Each deal is checked by counsel against the law in force on the day it ships.

Reading a COA

A Certificate of Analysis (COA) is the lab report for a specific lot. Before you rely on one, check:

1. The lab. Is it ISO/IEC 17025-accredited, the international standard for testing labs, and registered where the law requires it?
2. The lot. Does the lot or batch number on the COA match the number on the bags and the invoice?
3. The date. Is the sample recent enough to reflect the product as it is now?
4. Total THC. Is total THC reported, or can you calculate it from delta-9 THC and THCA?
5. Dry weight. Are the results on a dry-weight basis, with moisture reported?
6. The full panel. Does it cover pesticides, heavy metals, microbials and mycotoxins (toxins produced by moulds), and residual solvents for kief or extracts?
7. Who took the sample. Was it drawn by the lab or an independent sampler, or sent in by the seller?

How Tillmark tests

1. ReviewWe check the seller's COA and licence before a lot is offered.
2. SampleA sample goes to the buyer, and one is retained, sealed and labelled.
3. Re-testWhere agreed, an independent accredited lab re-tests before contract.
4. Pre-shipmentExport lots are tested again before they leave the US.
5. ArrivalExport lots are tested on arrival by the receiver's agreed lab.

The limits by destination

How each destination measures THC (total, or delta-9 only) is confirmed by counsel for every route before the first shipment.