The 0.2 / 0.3 / 1.0% lineages

Three numbers recur whenever hemp is defined by its THC ceiling — 0.2%, 0.3% and 1.0% — and each marks a different regulatory lineage.

The 0.2% line was the historical European Union standard: for years, only cannabis below 0.2% THC counted as agricultural hemp eligible for support. The 0.3% line is the North American standard, fixed by Canada decades ago and adopted by the US 2018 Farm Bill. In a notable convergence, the EU raised its own field limit from 0.2% to 0.3% under Regulation (EU) 2021/2115 (the reformed Common Agricultural Policy), applicable from 1 January 2023 — so the EU and US now share a threshold.

The 1.0% line is the outlier: Switzerland, outside the EU, treats cannabis below 1% THC as non-narcotic, and a few countries have explored similarly higher ceilings as a more scientifically generous definition of hemp. The lineage a country follows decides which varieties its farmers may legally grow — and how easily a crop tips over the edge into 'hot' hemp.