Diethyl pyrocarbonate: formation of urethan in treated beverages.

Isotope dilution analyses with tritium-labeled diethyl pyrocarbonate show that the carcinogen urethan is formed in orange juice, white wine, and beer. Commercial use of the antimicrobial food additive diethyl pyrocarbonate can result in urethan concentrations of 0.1 to 0.2 milligram per liter in orange juice and of the order of 1 milligram per liter in white wine and beer.