The U.S. Food and Drug Administration has decided that melamine, the toxic food additive that sickened tens of thousands of consumers in China this fall and killed cats and dogs around the world when it appeared in pet food last year, is safe when it occurs in U.S.-made food. After testing a wide range of food and finding levels up to 2.5 parts per million (ppm) in various kinds of food and up to 1 ppm in infant formula, it issued rulings finding that those levels could be considered safe.
Melamine is not allowed to be added to food anywhere, and scientists have not yet determined how it gets into food. However, melamine is not hard to find in the industrial environment in which food is made. It is found in some kinds of plastic, including food containers, in fertilizer, and in cleaning chemicals, including ones used to clean food containers, so perhaps those are the sources of melamine found in U.S.-made food.
China’s post-Olympics crackdown on the illegal use of melamine as an additive in dairy products led the FDA to look into the chemical, for which it previously had not adopted any safety standards. One has to assume that the tolerance of 1 ppm of melamine in infant formula and 2.5 ppm in other food is little more than a guess that will be further refined after the real scientific work is done.