- Associated Press - Thursday, February 17, 2011

BEIJING (AP) - China has warned dairy producers that inspectors are on alert for fresh milk tainted with the industrial chemical melamine and another toxic substance extracted from leather scraps, state media said Friday.

Both of the substances _ melamine and leather-hydrolyzed protein _ are used in watered-down milk to make it appear to have normal amounts of protein.

The China Daily newspaper reported that the Ministry of Agriculture issued a notice earlier this week on its website announcing it will carry out 6,450 random spot checks on fresh milk this year _ underscoring official concerns that dairy producers may still be trying to use illegal and dangerous methods to boost the protein content of their milk.

The random tests will look for trace amounts of melamine, the chemical that was found to be widely used in Chinese dairy products in 2008 and blamed for killing six children and sickening more than 300,000.

Thirty percent of the checks will also look for leather-hydrolyzed protein, a toxic substance extracted from leather scraps that manufacturers have used to artificially boost the protein content of milk, the paper said.

In March 2009, the Chenyuan Dairy Company in central China’s Zhejiang province was shut down by authorities after leather-hydrolyzed protein was found in its products, it said.

The China Daily said the substance contains toxic chemicals used to soften leather such as potassium dichromate and sodium dichromate. Consuming the chemicals can increase the risk of osteoporosis in humans, and could be deadly for children, it said.

Similar spot checks on 7,406 batches of fresh milk last year all came up safe, the paper said.

However, last year the government seized 2,132 tons of melamine-tainted milk powder during a six-month crackdown. The powder wasn’t newly manufactured but left over from 2008 or earlier.

After the melamine scandal broke in 2008, China ordered all contaminated dairy, including infant formula, yogurt and other products, burned or buried, but the government did not carry out the destruction itself. Some people apparently stockpiled the tainted products.

Health problems from melamine include kidney stones and kidney damage.

The latest alert couldn’t be found Friday on the Ministry of Agriculture’s website. Calls to the ministry’s press office rang unanswered.