ABSTRACT

Ethylene glycol (1,2-ethanediol), a bivalent aliphatic alcohol, is structurally similar to alcohol but contains a hydroxyl group on each carbon (1). It was synthesized about 1 0 0 years ago and was considered of little com­ mercial value until World War I, when a shortage of glycerin led to a widespread search for a practical non­ toxic substitute to be used as a solvent for drugs (2 ). Although it is now known that ethylene glycol is toxic, for many years it was believed to be nontoxic on the basis of two independent experiments 1 0 years apart, when two investigators drank small amounts of ethylene glycol without ill effects. For that reason, it has been included as a solvent in detergents, paints, lacquers, drugs, dyes, hy­ draulic brake fluid, polishes, cosmetics, and industrial solvents (3,4). It also has been used as a glycerine substi­ tute in enemas, as a coolant in the lunar module, and, in the past, as a preservative in juices and an ingredient in various early medicinals (5). Its most familiar use as radi­ ator antifreeze is based on its high boiling point and its ability to depress the freezing point of aqueous solutions (Table 38-1) (6 ).