HEMP Act Quadruples Legal THC Limit to 1%: What It Means for Farmers and Consumers

The Hemp Economic Mobilization Plan Act of 2025—the HEMP Act for short—is tackling agricultural policy with a major change that could shake up the hemp market. The core of this bill is simple but huge: it raises the legal limit of delta-9 THC in hemp from the current 0.3% to a full 1.0% on a dry weight basis (Sec. 2).

This isn't just a technical tweak; it's a fundamental change to how we define hemp. For farmers, this means more flexibility and potentially higher yields of usable crop, as a higher THC allowance means less risk of their entire harvest testing "hot" and being destroyed. For everyone else, it means the products derived from federally legal hemp are about to get significantly more potent, blurring the lines between hemp and low-THC marijuana.

The New 1% Rule: A Game Changer for Growers

Raising the THC cap to 1.0% (Sec. 297A(1) of the Agricultural Marketing Act of 1946) is a huge win for the hemp industry. Under the old 0.3% rule, farmers often struggled with genetics and environmental factors that pushed their crops over the limit, forcing costly destruction. Now, with a 1.0% cushion, producers can grow more robust plants and potentially develop new varieties, making hemp cultivation a much more reliable business proposition. This provision directly addresses one of the biggest headaches that has plagued hemp agriculture since 2018.

Clearing the Highway: New Rules for Transport

The HEMP Act also tightens up the rules for moving hemp across state lines, which has been notoriously confusing. Now, anyone transporting hemp must carry specific paperwork: either a valid license from the state or tribal government that covers the producer, or a lab certificate confirming the hemp has a delta-9 THC concentration of no more than 1.0% (Sec. 2). This aims to reduce confusion for truckers and law enforcement during transport, though it means states and tribal governments will have to quickly update their existing hemp plans to include this new documentation requirement.

Crucially, the bill also mandates better testing accuracy. Labs must now use methods where the measurement of uncertainty is not greater than 0.075 percent when testing for delta-9 THC. While this sounds hyper-technical, it’s actually a big deal because it standardizes how precise tests must be, helping to ensure that a farmer’s crop isn't accidentally classified as illegal based on a slightly imprecise test result.

The Fast Track: Why Speed Bumps Are Missing

One provision that stands out is the mandate for the Secretary of Agriculture to update federal regulations (Part 990 of Title 7, Code of Federal Regulations) to reflect these changes within a tight 90-day window. Even more notable, the Secretary is allowed to skip the usual public notice and comment period when making these changes (Sec. 2).

For the busy person, this means the rules governing a multi-billion dollar industry can be finalized behind closed doors without the usual public input from farmers, consumers, or even state regulators. While this speeds up implementation—which the industry will appreciate—it cuts out a key step of democratic oversight, meaning the final, critical details of how the 1.0% rule and testing standards will actually be enforced will be decided quickly and without public scrutiny.

Real-World Impact: Confusion at the Edges

While the 1.0% limit is a boon for growers, it creates significant challenges for law enforcement and consumers. If you’re a consumer, you need to know that products labeled as “hemp” could now be three times stronger than previous versions. This increased potency brings the legal definition of hemp much closer to marijuana, creating a potential enforcement headache for police who have to differentiate between 1.0% THC hemp and slightly higher THC marijuana—especially since the drug is still illegal under federal law. Furthermore, state and tribal governments must scramble to update their regulatory plans to align with the new federal standard, creating a temporary patchwork of rules that could lead to confusion until they catch up.