Melamine and cyanuric acid

Melamine is an industrial chemical with a high LD50 in laboratory animals. Because it is nitrogen rich, melamine has found illicit use as a substitute for protein in the production of foods and feeds with the unexpected consequences of high morbidity and mortality. There was an incident of pet food–contamination incident in 2007 in which melamine, combined with co-contaminant cyanuric acid, crystalized in the distal convoluted tubules of cats and dogs, resulting in renal failure. There was little or no cyanuric acid present in Chinese baby formula contaminated with melamine in 2008; however, neonates excrete uric acid, which combines with melamine in the urinary tract, forming uroliths in affected infants. Melamine is not currently considered to be mutagenic.