Isotope labelled Melamine (M208703), which forms synthetic resins with formaldehyde. It remains largely non-metabolized in male Wistar rats with 90% of the administered dose excreted in the urine (1,2) and thus acts as a non-protein nitrogen food additive found in milk (3). Drinking water contaminant candidate list 3 (CCL 3) compound as per United States Environmental Protection Agency (EPA), environmental, and food contaminants.