The nationwide check for the toxic chemical additive melamine in dairy products has found traces of the substance in three of China’s leading dairy brands, state media reported. The sweep found that nearly 10% of sample batches of products from dairy producers Mengniu and Yili tested positive for melamine, while 6.4% of batches from Shanghai-based Bright contained the chemical. Nestle and Sanyuan were declared "all clean." CCTV reported that adults weighing 60kg who drink less than 2 liters of melamine-contaminated milk a day face no health risk, though it did not mention the effects over a long period of time. The South China Morning Post quoted industry insiders as saying that the addition of melamine and many other chemical preservatives to milk is a common practice that has become "the unspoken rule in the industry."