

After the initial focus on Sanlu, further government inspections revealed that products from 21 other companies were also tainted, including those from Arla Foods– Mengniu, Yili, and Yashili. The Chinese government made the scandal public on 13 September. Fonterra alerted the New Zealand government and the NZ government confronted the Chinese government on 8 September. New Zealand dairy giant Fonterra, which owned a 43% stake in Sanlu, were alerted to the contamination on 2 August's Board meeting. On 2 August, Sanlu's Board decided to issue a trade recall to the wholesalers but did not inform the wholesalers the product was contaminated however, Shijiazhuang's deputy mayor, who was invited to attend, rejected trade recall and instructed the Board to "shut the mouths of the victims by money", "wait until the end of 2008 Beijing Olympics to end smoothly and then the provincial police would hunt the perpetrators". The culprit, melamine, was undetected in the tests until 1 August. Also on 20 May, the problem reached Sanlu's Board meeting the first time and they ordered multiple third-party tests.

One of the more notable early complaints was made on, when a mother posted online after she learnt that Sanlu donated the milk she had been complaining about to the orphans of the 2008 Sichuan earthquake. The timeline of the scandal dated back to December 2007, when Sanlu began to receive complaints about kidney stones.

The deaths of six babies were officially concluded to be related to the contaminated milk. 300,000 affected children were identified, among which 54,000 were hospitalized, according to the latest report in January 2009.

The chemical was used to increase the nitrogen content of diluted milk, giving it the appearance of higher protein content in order to pass quality control testing. The scandal involved Sanlu Group's milk and infant formula along with other food materials and components being adulterated with the chemical melamine, which resulted in kidney stones and other kidney damage in infants. The 2008 Chinese milk scandal was a significant food safety incident in China. Empty milk shelf in a Carrefour supermarket in China as a result of the scandal
