First baby milk formula, then dairy-based products from yogurt to chocolate, and now chicken eggs have been contaminated with melamine.
An admission that the industrial chemical is regularly added to animal feed in China has fueled fears that the problem could be more widespread, affecting fish, meat and possibly many other foods.
Melamine is rich in nitrogen, which means that it gives low-quality food and feed artificially high protein readings. But extremely high levels of melamine can cause kidney stones, and in some cases can bring on life-threatening kidney failure.
However, there have been no tests on melamine's precise effects in humans.
Until the contaminated baby formula became public in a few months ago, there was never any reason to. The situation has left consumers worldwide, particularly parents, worried about food products from China, and even those made elsewhere with ingredients imported from Chinese companies.