As of May 1, 2019, China will ban all variants of fentanyl. U.S. officials have been pressing for this broad ban as it would restrict a major supply source of these drugs to the U.S. They note the nation has been gripped by an opioid crisis fueled in part by exploited loopholes in Chinese law.

As reported by The Washington Post:

For years, China’s vast chemical and pharmaceutical industry exploited loopholes in Chinese law to create synthetic painkillers and their precursors that were not explicitly banned.

U.S. officials including Trade Representative Robert E. Lighthizer have pushed Beijing to significantly broaden its list of scheduled substances to cover the entire class of synthetic opioids, their analogues and precursors, and crack down on their unchecked production and export.

The New York Times reports additional details about the loopholes that were exploited and one that will still exist under the more stringent law:

China already treats more than two dozen variants of fentanyl and its precursors as controlled substances, thus strictly regulating their production and distribution, but it has banned those variants only after reviewing them case by case, a process that can be lengthy. And because so many more variants exist, and new ones are constantly being created, banning them as a broadly defined class could be far more effective.

…

But the ban does not cover all of the precursor chemicals used to make fentanyl and its analogues, according to a spokesman for Mr. Trump’s Office of National Drug Control Policy.

For more information:

China Bans All Types of Fentanyl, Cutting Supply of Deadly Drug to U.S. and Fulfilling Pledge to Trump (The New York Times)

China offers broad opioid curbs promised to Trump (The Washington Post)