Isotope labelled Urethane (U82500), which is a naturally occurring contaminant in fermented foods, particularly wine, stone-fruit brandies, and bread. This substance is reasonably anticipated to be a human carcinogen (1) despite being an additive in some alcoholic beverages and foods (2). It binds covalently with DNA however due to its low unavoidable daily intake, it is considered of negligible concern (3).Drinking water contaminant candidate list 3 (CCL 3) compound as per United States Environmental Protection Agency (EPA). Environmental contaminants; Food contaminants.