China's top environmental regulator calls on the country's environmental watchdog to reduce pollution when destroying contaminated dairy products.

A circular posted on the website of the Ministry of Environmental Protection yesterday, said all its departments are supposed to tighten monitoring and management measures when burning recalled dairy products in garbage incinerators.

Powdered milk and yogurt, among other tainted products, could also be put in land-fills if the amount was relatively small, the circular noted, adding that this must be approved first by the local environmental watchdog.

So far, the government has not released the amount of contaminated products collected in recalls.

According to the circular, companies and factories were required to have the type, source and quantity of the products being destroyed recorded and reported to the local environmental watchdog.

China's contaminated dairy product scandal was exposed on July 16 after 16 babies, who were fed milk made from powder produced by Sanlu Group, developed kidney stones.

An investigation revealed that melamine, a chemical used in manufacturing plastics, was added to sub-standard or diluted milk to make the protein levels appear higher.

Early this month, the government set temporary limits on melamine content in dairy products.