Melamine, an industrial chemical that made its way into China's dairy supplies, has been blamed in the death of four babies and the illnesses of 53,000 others. Now it has turned up in numerous Chinese-made exports, ranging from candies to yogurt to rice balls.

The British supermarket chain Tesco has removed Chinese-made White Rabbit Creamy Candies off its shelves as a precaution, as reports from Singapore and New Zealand state that the candy tested positive for melamine, an industrial chemical used to make plastics and fertilizer.

Health experts say melamine can cause kidney stones and lead to kidney failure. Infants are particularly vulnerable. More than a dozen countries have now banned or recalled Chinese dairy products.