CHINA— The Beijing News recently reported that some duck farmers in Hebei Province, China, feed their ducks with Sudan IV, a poisonous industrial dye, so that their ducks can produce eggs with red yolks.
The local people in Hebei don't consume these poisonous eggs but ship them to other regions. Beijing officials have banned the sale of red-yolk eggs produced from Hebei.
Red-yolk eggs are popular in China because Chinese people believe that ducks that are fed small fish and shrimp will produce eggs with red yolks, which are believed to be more nutritious than ordinary yolks.
An egg vendor said, “If ducks eat more small fish and shrimp, the yolks of their eggs will become redder. If they eat less, the color will be lighter.” However, a program on a state-controlled television station revealed that the red-yolk eggs with bright and pretty coloring contain the poisonous industrial dye called Sudan IV.
A reporter for a state-run media investigated dozens of duck farmers in Pingshan County and Jingxing County, in Shijiazhuang City. The reporter found that local duck farmers had added a then unidentified red substance to the ducks' feed, so the ducks would lay red-yolk eggs. The more of this substance added, the redder the yolks would be.
The reporter sent the yolks to the Institute of Food Safety at the National Academy of Inspection and Quarantine for testing. Test results showed that the egg yolks contained Sudan IV, a level three carcinogen, which may cause cancer when ingested by humans.
Red-yolk eggs found in markets and supermarkets were also tested. These eggs also contained Sudan IV.
On November 12, Beijing requested that markets stop selling all red-yolk eggs from Hebei Province and organized a team to investigate markets and malls to conduct further tests.