Chapter 5 - Ethylene Glycol and Other Glycols: Analytical and Interpretation Issues

Abstract

Glycol is a chemical compound that is diol containing two hydroxyl groups. In a clinical setting, most commonly encountered glycol is ethylene glycol. Other less frequently encountered glycols include diethylene glycol, propylene glycol, ethylene glycol monobutyl ether (EGBE), and ethylene glycol monomethyl ether (EGME). Glycols are associated with severe morbidity and an increased risk of death. Ethylene glycol is a colorless, odorless, and relatively nonvolatile liquid that is commonly used as an industrial chemical. It is a major ingredient of antifreeze and deicing solutions due to its high boiling point (197°C) and low freezing point. It may be accidentally ingested, particularly by children as it tastes sweet, or intentionally ingested by adults as an ethanol substitute or to inflict self-harm. Although ethylene glycol toxicity is uncommon, when it does occur, it can have a high morbidity or mortality. According to the 2016 Annual Report of the American Association of Poison Control Centers, there were 6325 single exposures to ethylene glycol with 32 fatalities. Similar to ethylene glycol, diethylene glycol is used in antifreeze, brake fluids, and deicing solutions. Propylene glycol is used as a solvent in commercial products as well as a diluent for oral, topical, and intravenous pharmaceutical preparations. Since it is significantly less toxic as compared to ethylene glycol, propylene glycol is the preferred antifreeze used in motor homes and recreational vehicles. Diethylene glycol is used in numerous products including solvents and brake fluids. Other glycol ethers, such as EGME/EGBE, are a group of compounds that are used as organic solvents in various products.