Field THC limit
The field THC limit is the maximum Δ9-THC a cannabis crop may contain to be classed as legal hemp rather than a controlled drug. It is measured on the flowering tops, on a dry-weight basis, usually within a short window before harvest.
Why it matters. This one number is the legal dividing line of the entire industry. A crop just over it can be reclassified as "marijuana," triggering destruction orders and licensing penalties. It dictates which varieties a farmer may plant and how testing is run.
How it varies. The United States sets the line at 0.3% total THC (post-decarboxylation — THC + THCA), under the 2018 Farm Bill and the USDA's 2021 final rule (7 CFR Part 990). The European Union raised its field limit from 0.2% to 0.3% for varieties eligible for Common Agricultural Policy support (Regulation (EU) 2021/2115, applicable from 2023). Other countries range from 0.2% up to 1.0%.
What the Atlas shows. The lens above maps each country's field THC limit — sourced and dated — so you can watch jurisdictions converge on 0.3%.
Common misconception. The limit applies to the crop in the field, not the finished product; THC in consumer goods is usually governed by separate, often stricter, rules.
The U.S. and EU both use 0.3% total THC by dry weight; the EU lifted its limit from 0.2% in 2023.
- European Commission — Hemp (0.3% THC limit & EU variety catalogue)
- US Congressional Research Service — The 2018 Farm Bill's Hemp Definition (0.3% delta-9 THC)
- Regulation (EU) 2021/2115 — CAP Strategic Plans
- USDA — U.S. Domestic Hemp Production Program
