Chinese Preserved Egg Illegally Preserved with Copper Sulfate

Preserved eggs are also known as hundred-year egg, thousand-year egg, thousand-year-old egg, and millennium egg, is a Chinese food ingredient made by preserving Duck Chicken or Quail eggs in a mixture of clay, ash, salt quicklime, and rice hulls for several weeks to several months, depending on the method of processing. By using copper sulfate they can cut the time to preserve the eggs in half thus increasing their profits

The China's State Food and Drug Administration has closed thirty factories that were using copper sulfate to process their eggs. Copper sulfate is an industrial chemical that is not approved for use as a food additive.  It is irritating to the eyes and skin, and also can be harmful if swallowed.

According to an anonymous worker who worked in a egg preserving plant it is common knowledge that Copper Sulfate is used. I do not know if the preserved eggs that are exported to other countries have been treated with Copper Sulfate. If I find out I will notify you.