EC

EC
Name	EC
Caption	Structural formula of EC
IUPAC	Ethyl carbamate
Other names	Urethane
Formula	C3H7NO2
Molar mass	89.09 g·mol−1
Appearance	Colorless crystalline solid
Melting point	25–26 °C
Boiling point	184–185 °C
Density	1.09 g·cm−3

EC

EC is a small organic compound historically known as ethyl carbamate and commonly referred to as urethane. It appears in diverse contexts spanning chemical synthesis, fermentation-derived food and beverage chemistry, toxicology, and historical pharmaceutical use. The compound has been the subject of regulatory scrutiny, industrial chemistry studies, and biochemical research involving metabolism, carcinogenicity, and analytical detection.

Definition and Nomenclature

EC is systematically named ethyl carbamate under IUPAC conventions and is also historically called urethane, a name that overlaps with the polymer class urethane derivatives. Synonyms encountered in older literature include ethylurethane and carbamic acid ethyl ester. Nomenclatural distinctions are important in regulatory documents from agencies such as International Agency for Research on Cancer, U.S. Food and Drug Administration, and European Food Safety Authority where terminology affects classification, labelling, and permissible limits.

History and Development

The compound was first synthesized in the 19th century during investigations by chemists working on carbamic acid derivatives concurrent with research by Friedrich Wöhler and contemporaries on urea and related species. In the early 20th century, EC entered medical use as an anesthetic and was promoted by physicians associated with institutions such as Johns Hopkins Hospital and proponents like F. G. Hopkins in experimental therapeutics, before being supplanted by safer agents like those studied at Harvard Medical School and institutions involved in anesthetic development. Industrial and food-chemistry attention grew in the mid-20th century with studies at laboratories affiliated with Nestlé, Heineken, and national research councils that identified EC formation during fermentation and storage. Regulatory responses emerged from bodies including World Health Organization, Food and Agriculture Organization, and national agencies with guidelines on monitoring in beverages and fermented foods.

Chemistry and Structure

EC is the ethyl ester of carbamic acid, featuring a carbamate functional group linking an ethyl moiety to an amide-like center. Its molecular geometry and spectroscopic signatures have been characterized using techniques employed at laboratories such as Royal Society of Chemistry facilities and research groups at Max Planck Institute for Coal Research. Key synthetic routes include reaction of ethanol with cyanate salts or transesterification from other carbamates, methods developed in chemical departments at institutions like Massachusetts Institute of Technology and University of Cambridge. The compound undergoes hydrolysis to ethanol and carbamic acid derivatives and participates in esterification and alkylation reactions studied in publications from American Chemical Society. Physical properties including melting point, boiling point, and solubility have been compiled by organizations such as National Institute of Standards and Technology.

Biological Roles and Mechanisms

EC is not a physiological metabolite but can form in biological matrices via chemical reactions during fermentation and metabolism involving precursors such as ethanol, urea, and amino acid derivatives. Formation pathways have been elucidated in biochemical studies from groups at University of California, Davis, University of São Paulo, and Chinese Academy of Sciences showing roles for cyanate, carbamoyl phosphate, and enzymatic or non-enzymatic conversions during processing. In vivo, EC is metabolized by hepatic enzymes including members of the Cytochrome P450 family and by hydrolases characterized in research centers like Mayo Clinic and Karolinska Institutet, producing reactive intermediates that can form DNA adducts—a mechanism implicated by laboratories at National Cancer Institute and Fred Hutchinson Cancer Research Center in mutagenesis studies.

Medical and Clinical Significance

Historically used as an anesthetic and adjuvant in chemotherapy trials in the early 20th century, EC’s medical application ceased due to toxicity concerns documented in clinical reports from institutions such as Cleveland Clinic and case series in journals associated with The Lancet. Carcinogenicity assessments by International Agency for Research on Cancer and long-term studies from National Toxicology Program classify EC as a probable human carcinogen based on animal bioassays from laboratories at National Institutes of Health and epidemiological investigations in cohorts studied by Harvard School of Public Health and others. Clinical toxicology reports describe hepatic, pulmonary, and neurologic effects after acute exposure, with management recommendations referenced in resources from World Health Organization poison centres and national poison control networks. Regulatory measures addressing EC levels in alcoholic beverages, fermented foods, and tobacco products have been implemented by agencies including European Commission and Health Canada.

Detection and Measurement

Analytical detection of EC in complex matrices employs chromatographic and mass-spectrometric techniques developed in analytical chemistry groups at University of Oxford, ETH Zurich, and Purdue University. Common methods include gas chromatography–mass spectrometry (GC–MS) with derivatization protocols standardized in interlaboratory studies coordinated by International Organization for Standardization and liquid chromatography–tandem mass spectrometry (LC–MS/MS) methods validated in laboratories at Agilent Technologies collaborations. Sample preparation approaches such as solid-phase extraction, headspace analysis, and stable-isotope dilution have been refined in proficiency trials organized by Association of Official Analytical Collaboration and national metrology institutes. Limits of detection and quantification, calibration strategies, and quality-control practices are described in technical reports from European Food Safety Authority and certified testing labs accredited under ISO/IEC 17025.

Category:Organic compounds