The World Health Organisation issued safety limits for melamine levels in food.
It is the first time WHO experts have issued safety limits for the use of the industrial chemical and they stressed that melamine should not be used in food at all.
The so-called Tolerable Daily Intake (TDI) has been fixed at 0.2 mg per kilogram of body weight. The WHO said on Friday this means that a person who weighs 50kg can tolerate up to 10mg of melamine per day.
However, the agency stressed the industrial chemical "should not be in food" even though traces are sometimes unavoidable.
China said on Monday 294,000 children had been made ill by consuming dairy products containing melamine, with 154 still in serious condition.
Melamine can cause kidney stones if taken in excessive levels.
It has been mixed into Chinese milk and dairy products to give them the impression of having higher protein content.
China said six deaths since September may have been caused by tainted dairy products. The confirmed death toll so far is three infants.