Food safety standards improved after a crisis that tarnished the nation's image
Could another health crisis like the melamine contamination case happen again? How was it allowed to happen in the first place?
There were many causes: simple greed and ignorance, a porous food-safety monitoring system, and company executives and government officials keen to cover up a scandal that might affect profits and tarnish the country's image at the crucial time of the Beijing Olympics.
As facts have emerged, it has become clear that opportunities to act earlier were missed.
Sanlu, the dairy based in Hebei at the centre of the scandal, received its first consumer complaint about kidney problems related to its milk powder in December 2007.
But it was not until May last year that the company's management held its first meeting on the issue.
Sanlu said it informed city authorities in Shijiazhuang about melamine contamination on August 2. The Hebei provincial government - which is also based in Shijiazhuang - said it was not informed by the city authorities until September 8, the same day the New Zealand government warned Beijing about the contamination.
At least eight central government officials were removed from office, and two dozen or so Shijiazhuang officials were replaced - including the party secretary and the mayor.
A total of 21 people received criminal sentences, ranging from Sanlu executives to milk farmers and middlemen in the dairy industry.
Of course, the public was quick to notice that no cadres were criminally charged, and the only two people who received death sentences were a lowly manufacturer of 'protein powder' that contained melamine, and a milk-station operator who added the powder to his milk.
The charge against Sanlu boss Tian Wenhua was changed at the last minute from manufacturing dangerous products to manufacturing substandard products - for which the maximum sentence is life imprisonment.
One positive outcome has been an improvement in mainland food-safety standards.
The system under which certain big-name brands could be exempted from government inspections - Sanlu was one of them - has been scrapped. The requirement for using food additives has been overhauled.
And detailed regulations on every link of the farm-to-shelf process of a dairy product have been introduced.
'China has become a safer place today,' said Professor Luo Yunbo of the China Agricultural University. 'But what a heavy price we paid.'
Melamine first became known as a danger not through milk powder, but as an additive in mainland-made pet food bound for the United States, and was discovered in late 2007.
Luo said he and his colleagues tried to warn companies manufacturing protein-rich food products to be careful about using melamine in order to boost protein levels. He contacted technical personnel at companies including Sanlu, but as they could not say how dangerous melamine could be, the firms did not heed the advice.
Before the scandal, melamine was considered to be about as toxic as table salt. It was used to produce plastic and occasionally found its way into food owing to their plastic containers.
It was only after mainland children began to fall ill did scientists begin to test it properly and discover that it could lead to kidney stones.
'It's very difficult to create methods to test for things when you don't know what they are. And if they are present at a very low level, it is nearly impossible,' said testing methodology expert Dr Andreas Breidbach of the European Commission's Institute for Reference Materials and Measurements.
Melamine is now monitored around the globe, although the tolerable level differs from 0.25mg/kg in Taiwan, to 1mg/kg on the mainland and 2.5mg/kg in the European Union. At its peak, Sanlu was packing 2,500mg/kg into some products.
Meanwhile, the wife of Geng Jinping , the milk farmer sentenced to death, is still petitioning for the release of her husband, whom she said was told by Sanlu milk collectors to add 'protein powder' to enhance the quality of the milk.
'How can my husband with the alleged addition of 434kg of protein powder be responsible for making 300,000 babies ill?' she said.
After being kicked out of their house and milk-collection station in Hebei's Zhengding county, she is now a street hawker with her son in Shijiazhuang.
Brought to book
The scandal led to many officials being removed from office
The number of people who received criminal sentences is: 21