Ethyl Carbamate
Ethyl carbamate is a process contaminant that is sometimes found in fermented foods and alcoholic beverages. Ethyl carbamate (also called urethane) can form during the fermentation and storage of foods and beverages that naturally contain nitrogen-rich compounds such as urea, citrulline, and cyanate. Low levels of ethyl carbamate can be found in breads, soy sauce, beer, and wine. In the case of beer, wine, and bread, ethyl carbamate can form when there is a reaction between ethanol and nitrogen-rich compounds produced by yeast during brewing and fermenting. Higher levels of ethyl carbamate can occur in distilled alcoholic spirits, especially those made from sugar cane and stone fruits, due to the presence of ethyl carbamate precursors in the raw materials and the high temperatures used during distillation. Industry practices can reduce the levels of ethyl carbamate in finished products.
The FDA has worked with domestic manufacturers and other government agencies to set voluntary limits for ethyl carbamate in wines and distilled spirits and to share information on reducing ethyl carbamate exposure.
In laboratory studies, high doses of ethyl carbamate have been shown to cause cancer in animals. The United States National Toxicology Program lists ethyl carbamate in the 15th Report on Carcinogens as “reasonably anticipated to be a human carcinogen” based on data from animal studies.
In 2005, the 64th Joint Food and Agriculture Organization/World Health Organization Expert Committee on Food Additives (JECFA) estimated exposure to ethyl carbamate from foods and alcoholic beverages and determined that the dietary risk from foods, excluding alcoholic beverages, was of low concern. FDA experts participated in this session. However, ethyl carbamate exposure for consumers of alcoholic beverages was significantly higher, leading JECFA to suggest that mitigation measures to reduce ethyl carbamate in some alcoholic beverages are needed. Other government agencies, including the FDA, have reached similar conclusions, and there have been worldwide efforts to reduce ethyl carbamate levels in alcoholic beverages.
Monitoring data from JECFA, Canada, and the United States suggest that ethyl carbamate levels in alcoholic beverages have decreased since the 1990s. Therefore, exposure estimates from the 1990s may be higher than current dietary exposure to ethyl carbamate from alcoholic beverages. As new data on ethyl carbamate levels becomes available, FDA experts will consider these data in their continued evaluation of exposure and potential risk.
The FDA’s Center for Food Safety and Applied Nutrition (CFSAN) monitors contaminant levels in foods and beverages, including ethyl carbamate, to inform FDA actions and protect public health.
In 1988, the FDA developed a method to detect and quantify ethyl carbamate and conducted surveys to determine the amount of ethyl carbamate that naturally occurs in alcoholic beverages, bread and other fermented foods. See Publications by the FDA on Ethyl Carbamate for sampling data on foods other than alcoholic beverages.
The FDA shares responsibility for alcoholic beverage regulation with the U.S. Department of Treasury Alcohol and Tobacco Tax and Trade Bureau (TTB). TTB monitored levels of ethyl carbamate in distilled spirits, wine, and malt beverages between 1988-1998. TTB published their method for detecting ethyl carbamate in alcoholic beverages in the Journal of AOAC International.
In FY2020-21, the FDA and TTB cooperated on the sampling and analysis of 278 additional alcoholic beverages. Survey results showed that average ethyl carbamate levels in distilled spirits and wine decreased in 2021 from levels reported in 1988, and overall ethyl carbamate levels in malt beverages remained low. This decrease in ethyl carbamate concentrations in distilled spirits and wine over time suggests that industry mitigation efforts have been effective. See the FDA’s presentation for further details on this survey of alcoholic beverages.
- 2022 FDA Presentation on Ethyl Carbamate (PDF: 629KB)
- Ethyl carbamate levels resulting from azodicarbonamide use in bread. Benjamin J. Cañas, Gregory W. Diachenko, Patricia J. Nyman. Food Additive & Contaminants. 1997, 14(1): 89-94.
- Determination of ethyl carbamate in alcoholic beverages and soy sauce by gas chromatography with mass selective detection: collaborative study. Benjamin J. Cañas, Frank L. Joe, Gregory W. Diachenko, Gordon Burns. Journal of AOAC International. 1994, 77(6): 1530-1536.
- Ethyl carbamate levels in selected fermented foods and beverages. Benjamin J. Cañas, Donald C. Havery, Louis R. Robinson, Michael P. Sullivan, Frank L. Joe Jr., Gregory W. Diachenko. Journal of Association of Official Analytical Chemists. 1989, 72(6): 873-876.
- Ethyl carbamate in alcoholic beverages and fermented foods. Gregory W. Diachenko, Benjamin J. Canas, Frank L. Joe, Michael DiNovi. ACS Symposium Series. 1992, 484: 419-428.
- Quantitation of ethyl carbamate in whiskey, sherry, port, and wine by gas chromatography/tandem mass spectrometry using a triple quadrupole mass spectrometer. William C. Brumley, Benjamin J. Canas, Gracia A. Perfetti, Magdi M. Mossoba, James A. Sphon, Paul E. Corneliussen. Analytical Chemistry. 1988, 60(10): 975-978.
- Rapid gas chromatographic method for determining ethyl carbamate in alcoholic beverages with thermal energy analyzer detection. Benjamin J. Canas, Donald C. Havery, Frank L. Joe, Jr. Journal of Association of Official Analytical Chemists. 1988, 71(3): 509-511.
- Occurrence of Ethyl Carbamate in Foods and Beverages: Review of the Formation Mechanisms, Advances in Analytical Methods, and Mitigation Strategies. Eileen Abt, Victoria Incorvati, Lauren Posnick Robin, Benjamin W. Redan. Journal of Food Protection. 2021, 84(12): 2195-2212.
FDA has worked with the distilled spirits and wine industries to limit ethyl carbamate in alcoholic beverages. This includes voluntary agreements from the Distilled Spirits Council of the United States (DISCUS) and the U.S. wine industry [1]. In 1987, DISCUS made a voluntary commitment to reduce ethyl carbamate to a target level of 125 ppb or less in whiskey and to conduct research on ethyl carbamate formation. Based on information received from DISCUS, whiskey distillers participating in the DISCUS program have been able to achieve the target level of 125 ppb in recent years. In 1988, the U.S. wine industry agreed to set target goals for ethyl carbamate in table and dessert wines and committed resources for research and monitoring of ethyl carbamate.
In 1997, the University of California, Davis, in cooperation with FDA and the Wine Institute, published an Ethyl Carbamate Preventative Action Manual (English Version, Italian Version) that outlines strategies to help growers and manufacturers reduce ethyl carbamate in wine. One method to reduce ethyl carbamate levels in wine is the use of the food enzyme urease. The use of urease in wine was affirmed as GRAS by FDA in 1992 (21 CFR 184.1924). Certain strains of yeast and bacteria are also known to alter the concentrations of ethyl carbamate precursor compounds, and the FDA has evaluated a GRAS notice relating to this application for a yeast strain used as a starter culture in alcoholic beverage production.
FDA experts participate in an international standard-setting body, the Codex Alimentarius Commission (Codex). The purpose of Codex is to protect the health of consumers and promote fair trade practices by adopting scientifically based standards, guidelines, and codes of practice across all areas of food safety and quality. Codex work includes reviewing scientific data and information on good manufacturing practices concerning ethyl carbamate and other contaminant levels in foods. Recommendations from Codex about reducing ethyl carbamate in distilled spirits made from stone fruits can be found in the Code of Practice for the Prevention and Reduction of Ethyl Carbamate Contamination in Stone Fruit Distillates.
1. See Federal Register notice: Urethane in Alcoholic Beverages; Research and Surveys; Availability (55 FR 10816, March 23, 1990).
The Dietary Guidelines for Americans, 2020-2025 recommends limiting alcoholic beverages (if consumed) to 2 drinks or less a day for men and 1 drink or less a day for women. See Top 10 Things You Need to Know About the Dietary Guidelines for Americans, 2020-2025.