"China customs detected ractopamine in a batch of frozen beef omasum (the third compartment of the stomach) products exported to China from these establishments and destroyed this batch of products in accordance with their regulations," an FSIS spokesperson said, Reuters reported.
Ractopamine, a feed additive, can be fed to livestock and poultry to improve weight gain and feed efficiency and reduce carcass fat.
About 160 countries ban the use of ractopamine on grounds that it can be harmful to humans.
The U.S. and Canada are among the countries that allow the use of ractopamine. And the FDA has determined that meat from animals fed ractopamine is safe for human consumption.
China also placed a ban on a port in California on May 27.
The Cool Port in Oakland is also implicated in the temporary ban.
This temperature-controlled distribution center can help support 1 million tons of beef and pork shipments annually.
It’s unclear why China placed the restrictions on the port.