(DEG) is a commonly used agent but a less common toxin than ethylene glycol. DEG causes an anion gap metabolic acidosis that has been associated with significant historical poison outbreaks. It was the toxin implicated in the Massengill antibiotic poison epidemic in 1937 that was responsible for the first drug and pharmaceutical regulation in the United States. That regulation was the precursor to what has today become the U.S. Food and Drug Administration (FDA). DEG was also implicated in other mass outbreaks from contaminated over-the-counter pharmaceuticals in Haiti (1995-1996), Bangladesh (1990), and Panama (2006).^14–16 This substance is used in the formulation of brake fluid and was once thought to be a nontoxic, less expensive diluent. DEG is a potent renal toxin that can cause a progressive and profound anion gap metabolic acidosis.