Ethyl Carbamate - Hazards

Hazards

Ethyl carbamate is not acutely toxic to humans, as shown by its use as a medicine. Acute toxicity studies show that the lowest fatal dose in rats, mice, and rabbits equals 1.2 grams/kg or more. When ethyl carbamate was used medicinally, about 50 percent of the patients exhibited nausea and vomiting, and long time use led to gastroenteric hemorrhages. The compound has almost no odor and a cooling, saline, bitter taste.

Studies with rats, mice, and hamsters has shown that ethyl carbamate will cause cancer when it is administered orally, injected, or applied to the skin, but no adequate studies of cancer in humans caused by ethyl carbamate has been reported due to the ethical considerations of such studies. However, in 2007, the International Agency for Research on Cancer raised ethyl carbamate to a Group 2A carcinogen that is "probably carcinogenic to humans," one level below fully carcinogenic to humans. IARC has stated that ethyl carbamate can be “reasonably anticipated to be a human carcinogen based on sufficient evidence of carcinogenicity in experimental animals.” In 2006, the Liquor Control Board of Ontario in Canada rejected imported cases of sherry due to excessive levels of ethyl carbamate.

Alcoholic beverages, particularly certain stone-fruit spirits and whiskies, tend to contain much higher concentrations of urethane. Heating (e.g., cooking) the beverage increases the ethyl carbamate content, and some concern exists over shipping wines to overseas markets in containers that tend to overheat. In addition, urethane has a tendency to accumulate in the human body from a number of daily dietary sources, e.g., alcohols, bread and other fermented grain products, soy sauce, orange juice and commonly consumed foods. Hence, exposure risk to human health is increasingly evaluated on the total ethyl carbamate intake from the daily diet (WHO refers to this as "margin of exposure" or MOE), of which alcoholic beverages often provide the most significant portion.

Studies in Korea (2000) and Hong Kong (2009) outline the extent of the accumulative exposure to ethyl carbamate in daily life. Fermented foods such as soy sauce, kimchi, soybean paste, breads, rolls, buns, crackers and bean curd, along with wine, sake and plum wine, were found to be the foods with the highest ethyl carbamate levels in traditional Asian diets.

In 2005, the JECFA (Joint FAO/WHO Expert Committee On Food Additives) risk assessment evaluation of ethyl carbamate concluded that the MOE intake of ethyl carbamate from daily food and alcoholic beverages combined is of concern and mitigation measures to reduce ethyl carbamate in some alcoholic beverages should continue. There is little doubt that ethyl carbamate in alcoholic beverages is very important to health authorities, while the cumulative daily exposure in the typical diet is also an issue of rising concern that merits closer observation. The Korean study concluded, "It would be desirable to closely monitor ethyl carbamate levels in Korean foods and find ways to reduce the daily intake."

The IARC evaluation has led to the following US regulatory actions:

• NESHAP: Listed as a Hazardous Air Pollutant (HAP)
• Comprehensive Environmental Response, Compensation, and Liability Act: Reportable Quantity (RQ) = 100 lb
• Emergency Planning and Community Right-To-Know Act, EPA’s Toxics Release Inventory: A listed substance subject to RCRA reporting requirements
• RCRA Listed Hazardous Waste: substance - U238