Beijing added two fentanyl-making ingredients to its export control list for the US, Canada, and Mexico on Sept. 22, increasing the total count of restricted substances. These precursor chemicals now require an official export license for shipments to the three North American nations to limit the production of synthetic opioids.

The updated regulations bring the total number of controlled fentanyl precursors to 18 chemicals. The South China Morning Post reported that the measure aims to regulate the trade of chemical ingredients shipped from China to North American markets to prevent the manufacture of illicit drugs.