China is cracking down on two chemical additives used illegally on pig farms - and threatening to execute farmers who break the law banning their use.

But one of the dangerous chemicals is legal in Korea and fed to some domestic pigs. The chemical, ractopamine, can cause respiratory problems or kidney malfunction in humans, even if only small amounts are ingested.

More than 150 countries prohibit the use of ractopamine, including Taiwan, Malaysia and the European Union, although 20 countries allow it, including the United States, Australia, and Brazil.

“Because many countries currently prohibit the use of ractopamine, the Korean government should reconsider [the chemical’s] safety,” said Lee Mun-han, a professor at Seoul National University’s College of Veterinary Medicine. 

On March 15, the state-run China Central Television (CCTV) reported that a certain kind of lean pork marketed under the term “Genmijeo” was found to contain two hazardous chemicals, clenbuterol and ractopamine, which Chinese hog farmers mixed into animal feed. 

The chemicals were banned in China in 2002.

Health officials say clenbuterol causes muscle spasms or arrhythmias even in small doses. Ractopamine can affect humans even in doses as low as 0.01 parts per million.

The CCTV report didn’t cite how many pigs in China were fed the poisonous chemicals, but a CCTV reporter visited about 10 hog farms in Nanjing city and found farmers using the chemicals.

After the report, panic spread to Hong Kong, which imports much of its pork from China, and the Chinese government announced it would execute farmers using the chemicals and others involved in their trade. 

The Korean government banned clenbuterol in 2006, but it has allowed the use of ractopamine since 2001. 

Jo Byeong-hun, a researcher for the National Veterinary Research and Quarantine Service, said Korea hasn’t imported any pigs from China since 2007, but some processed foods made from Chinese pork are imported.

“Starting today, we will inspect whether the processed foods contain more than the permissible amount of ractopamine,” Jo said.


By Park Tae-kyun, Kim Hee-jin [heejin@joongang.co.kr]