China’s Ministry of Agriculture (MOA) said the quality and safety of fresh milk on the Chinese market was "generally safe" and that no leather hydrolyzed protein or other prohibited materials had been detected in its tests in recent years.
Authorities will "harshly crack down upon and punish companies that illegally process or produce milk using leather protein," the country’s product quality watchdog said in a statement on its website.
Allowed in animal feed
Leather hydrolyzed protein is derived from scraps of animal skin and contains toxic chemicals including potassium dichromate and sodium dichromate used to soften the leather. Users are at risk of developing osteoporosis from the toxic chemicals.
Its use as an additive in animal feed is allowed but the government in February 2009 banned the adding of leather protein to food consumed by humans, said the General Administration of Quality Supervision, Inspection and Quarantine.
However, unscrupulous food producers have been found adding it to dairy products to make them appear to have higher amounts of protein, the quality watchdog said.
Neither the government statement nor Chinese media reports said use of the substance was widespread.