109: Toxic Alcohols

HISTORY AND EPIDEMIOLOGY

Methanol was a component of the embalming fluid used in ancient Egypt. Robert Boyle first isolated the molecule in 1661 by distilling boxwood, calling it spirit of box.²⁹ The molecular composition was determined in 1834 by Dumas and Peligot, who coined the term “methylene” from the Greek roots for “wood wine.”²⁰² Industrial production began in 1923, and today most methanol is used for the synthesis of other chemicals. Methanol containing consumer products that are commonly encountered include model airplane and model car fuel, windshield washer fluid, solid cooking fuel for camping and chafing dishes, photocopying fluid, colognes and perfumes, and gas line antifreeze (“dry gas”). Methanol is also used as a solvent by itself or as an adulterant in “denatured” alcohol.¹³⁸ Most reported cases of methanol poisoning in the United States involve ingestions of one of the above products, with more than 60% involving windshield washer fluid,⁵⁸ although most inhalational exposures involve carburetor cleaner.⁸⁷ In a Tunisian series, ingested cologne was the most common etiology.³⁰ In a Turkish series, cologne was also most common, accounting for almost 75% of ingestions.¹²⁹ Perfume was one of several exposures in a patient with methanol poisoning in a report from Spain,¹⁷³ and methanol poisoning from cologne has also been reported in India.¹² There are sporadic epidemics of mass methanol poisoning, most commonly involving tainted fermented beverages.^23,130 These epidemics are a continuing problem in many parts of the world.^{16,146,153,166,187,218,257}

Ethylene glycol was first synthesized in 1859 by Charles-Adolphe Wurtz and first widely produced as an engine coolant during World War II, when its precursor ethylene oxide became readily available.⁷⁰ Today its primary use remains as an engine coolant (antifreeze) in car radiators. Antifreeze used in gas tanks generally contains methanol. Because of its sweet taste, it is often consumed unintentionally by animals and children. Aversive bittering agents may be added to ethylene glycol containing antifreeze to try to prevent ingestions by making the antifreeze unpalatable, an approach required by law in two states. However, there is no evidence that this strategy is effective, and comparisons in poison center data between ­ethylene glycol ingestions where bittering agents were required and where they were not have revealed no significant differences in frequency or ­volume of ingestion, or any other outcome variable (Chap. 135).^253,254

Isopropanol is primarily available as rubbing alcohol. Typical household preparations contain 70% isopropanol. It is also a solvent used in many household, cosmetic, and topical pharmaceutical products. Perhaps because it is so ubiquitous, inexpensive, and with a common name that contains the word “alcohol”, isopropanol ingestions are the most common toxic alcohol exposure reported to poison centers in the United States,³⁶ typically in cases where it was used as an ethanol substitute ...