Glycol Ether Toxicology

Glycol ethers (GE) are a group of compounds used for their solvent properties and are produced from either ethylene oxide (E-series) or propylene oxide (P-Series). Unlike their parent compounds, glycol ethers have two different hydrocarbon substituents attached to the oxygen molecule, one of which carries a hydroxyl group. The distinction between the two groups is essential to their industrial application. The E-series is used in cleaning solutions and brake fluid, whereas the P-series is found in cosmetics, sunscreen, and pharmaceuticals. When the compound was first developed in the 1930s under the name Cellosolve®, it was considered relatively nontoxic. However, the E-series use is declining after discovering its toxicological side effects.

The chemical name for a GE can vary based on the hydrocarbon chain and orientation of the substituents. Common examples include 2-methoxyethanol (EGME), diethylene glycol (DEG), and 2-butoxyethanol, also known as ethylene glycol butyl ether (EGBE). Please note that Cellosolve®, EGME, and ethylene glycol butyl ether are essentially the same compound. For brevity, the remainder of this article will use the term GE unless otherwise specified. Finally, like other organic toxins carrying hydroxyl group(s), GEs are broadly classified as toxic alcohols.