Explainer

Why Is Antifreeze So Delicious?

Engine Fluid 101.

A New Jersey woman has pleaded not guilty to murdering her brother-in-law with an antifreeze-spiked drink. According to prosecutors, Maryann Neabor’s weapon of choice was a blended concoction of pineapple juice, maraschino cherries, and several ounces of the deadly automotive additive. As in similar past cases, the victim was oblivious to his drink’s lethality, since antifreeze actually tastes pretty good. Why is something so deadly so delicious?

Ethylene glycol is the ingredient that makes antifreeze tasty. Though colorless and odorless, the syrupy alcohol derivative—which is excellent at lowering the freezing points of vital engine fluids—has a sweet taste that jibes well with soda, juice, and other sugary beverages. As many concerned pet owners and parents are well aware, dogs, cats, and kids are prone to lap up puddles of antifreeze left on garage floors. Every year, 90,000 animals and 4,000 children ingest the toxic liquid; if not treated immediately, the consequences of the poisoning can include renal or cardiovascular failure, brain damage, and death.

For obvious reasons, there’s been quite a bit of agitation for safer, less scrumptious antifreeze. One solution has been the development of antifreezes, including one called SIERRA, that replace ethylene glycol with propylene glycol, a liquid that’s nontoxic enough to be used as a sweetener in children’s cough syrup. But propylene glycol costs significantly more than ethylene glycol.

Lawmakers have also taken up the cause. Oregon and California both require that antifreeze manufacturers add a bittering agent to their products, in order to make them unpalatable to pets and children (and, one would presume, potential murder victims). The city of Albuquerque, N.M., passed a similar measure in January, nicknamed “Scooby’s Law” after a local golden retriever who was maliciously poisoned with antifreeze. And Congress is currently considering a bill, the Antifreeze Safety Act, that would mandate the addition of yucky-tasting denatonium benzoate to all antifreeze products containing more than 10 percent ethylene glycol.

Bonus Explainer: There is a popular misconception that some unscrupulous wine growers add antifreeze to their products, in order to cheaply sweeten otherwise shoddy vintages. This myth has been in part perpetuated by a classic Simpsons episode in which Bart helps capture a French duo trying to pull such a scam. While it’s true that some Austrian winemakers were caught adding an illicit sweetening agent in 1985, the substance in question was diethylene glycol, not ethylene glycol. Though you probably wouldn’t want to chug a gallon of it, diethylene glycol is nowhere near as harmful as its similarly named chemical cousin.

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