Two rows of empty wine glasses and a bottle of liqueur being poured into one glass.

Ethyl Carbamate (EC)

General

Ethyl carbamate (EC), also known as urethane, is a naturally occurring compound found in various fermented foods and beverages. It is a byproduct of the fermentation process involving ethanol and nitrogen-rich compounds during brewing and fermenting. High levels of EC can occur in distilled alcoholic spirits, due to the presence of ethyl carbamate precursors in the raw materials such as sugar cane and stone fruits, and the high temperatures used during distillation. Low levels of EC can be found in soy sauce, breads, beer and wine. Factors influencing its formation include temperature, pH, storage conditions, and the presence of certain microorganisms such as yeasts.

Animal studies have shown that chronic exposure to EC can lead to the development of tumors in various organs. The International Agency for Research on Cancer (IARC) classifies it as Group 2A - "probably carcinogenic to humans". 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. The Joint Food and Agriculture Organization (FAO)/World Health Organization (WHO) Expert Committee on Food Additives (JECFA) assessed the exposure to EC from foods and alcoholic beverages. They concluded that the risk associated with EC intake from foods (excluding alcoholic beverages) would be of low concern. These risk assessments have encouraged the establishment of allowable limits for EC in beverages by different governmental agencies (Abt et. al., 2021). For example, allowable limits in distilled spirits (e.g., tequila, whiskey, and vodka) range from 125 μg/L in the United States to 210 μg/L in Brazil.

The most widely used technique for detecting and quantifying EC is Gas Chromatography-Mass Spectrometry (GC-MS). Solid-Phase Microextraction (SPME) is used in conjunction with GC for effective sample preparation and detection of ethyl carbamate in complex food matrices. These methods are reliable, but accurate measurements require rigorous calibration and validation of the techniques involved.

Guidance for Industry

FDA has worked with the distilled spirits and wine industries to limit ethyl carbamate in alcoholic beverages. In 1997, the University of California, Davis, in cooperation with FDA and the Wine Institute, published an Ethyl Carbamate Preventative Action Manual 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 Codex Alimentarius Commission (Codex) reviewed scientific data and information on good manufacturing practices concerning ethyl carbamate and other contaminant levels in foods and made recommendations about reducing ethyl carbamate in distilled spirits made from stone fruits.

Information for Consumers to Reduce Exposure

The risk associated with EC exposure from food appears to be minimal due to its low concentration. Consumers should limit the intake of alcoholic beverages to reduce exposure.

Resources