BEIJING - CHINA faces a new problem with the tainted milk that has sickened babies and battered public confidence: how to get rid of the toxic stuff.

Tens of thousands of tonnes of milk laced with melamine, a chemical used in making fertiliser and plastics, have been pulled from shelves and warehouses since September.

The Health Ministry has not released a total figure for the amount of impure dairy products recalled or said how much has been destroyed.

But last month alone, more than 32,000 tonnes - enough to fill about 23 Olympic-size pools - were disposed of in a single province, Hebei, according to the official Xinhua news agency.

Local governments now face the huge - and costly - problem of safely disposing of the products.

With confidence in the government's food safety standards battered by the scandal, Beijing has issued new guidelines on how to destroy the tainted products.

The government's advice: burn or bury.

It recommends burning the milk in large-capacity incinerators or, if such facilities are not available, burying small amounts in landfills - as long as local environmental bureaus approve.

Burning or burying breaks down melamine and neutralises its toxicity, said Mr Peter Ben Embarek, a Geneva-based scientist at the World Health Organisation's food safety department.

But both methods do not come cheap. Burning the tainted milk costs about US$100 (S$152) a tonne, said Chinese officials.

Putting the milk in landfills is cheaper - about US$29 a tonne - though there are limits on how much can be buried each day.

At the Jinniu Energy Company in Hebei's Xingtai city, some 1,200 tonnes of milk powder were incinerated over the past month.

'In the first two or three days, progress was slow due to our lack of experience, but it has speeded up,' said company administrator Wang Jian, adding that the air in the incinerator was treated to remove pollutants.

But some local authorities have come up with more creative solutions: mixing the tainted milk into cement, bricks and even coal.

At a factory in the southern city of Guangzhou, contaminated milk powder was incinerated, then mixed into cement, said Guangzhou's food safety office director Wang Fan.

The city was also considering mixing the residue into bricks, said reports.

At a power plant in the coastal city of Qingdao, some eight tonnes of milk powder were poured into a towering pile of coal, which was then burned to generate electricity.

Despite the guidelines on proper disposal of the tainted milk, there have been violations. In Guangzhou, the local government took over responsibility for disposal after one garbage company poured milk into a city river, causing concerns among residents about the safety of the water supply. The company was fined US$29,000.

AP