Updated 9:18 pm

Bottles of Fireball whiskey, the insanely popular cinnamon-flavored frathouse favorite, are being recalled in some European countries—because it’s got too much of a chemical used in antifreeze (among other things) inside.

Late last week, the whiskey’s European bottler informed the makers of Fireball that they were out of compliance with European regulations. The Fireballers prepare two versions: a recipe for Canada and the United States containing the chemical, propylene glycol, and a European version that has less of the stuff. Propylene glycol is used for a variety of industrial, cosmetic, and food production uses. In your Prestone Low-Tox, it's an antifreeze. In Fireball, it's used as a sweetener, its makers say. (And yes, according to the Centers for Disease Control, it's "generally regarded as safe for use in food.")

“It appears that we shipped our North American formula to Europe and found that one ingredient is out of compliance with European regulations,” a Fireball spokeswoman told The Daily Beast in an email. “Finland, Sweden and Norway have asked to recall those specific batches which is what we are doing.” (There’s no word of an American recall.)

Fireball has exploded in popularity in the United States, prompting expansion in Europe. Earlier this year, the fraternity news website Total Frat Move declared Fireball “the most popular shot for college students.”

In 2011, Fireball had just $1.9 million in sales in the United States, reported Bloomberg Businessweek. By 2013, that figure rose to $61 million, surpassing Jameson Irish whiskey and Patron tequila. These figures don’t include sales at bars, meaning that sales of the drink were likely even higher.

And when a wedding party attached a GoPro camera to a bottle of the whiskey, the resulting video went viral. “One of the most unique wedding videos ever,” declared Buzzfeed.

One key ingredient of the stuff: Propylene glycol, a synthetic liquid that absorbs water. The Centers for Disease Control note that it is used to “make polyester compounds, and as a base for deicing solutions.” In food production, the CDC adds, the syrupy stuff also can be used to "maintain moisture... It is a solvent for food colors and flavors."

Fireball insists that there are “no health risks” and that “all Fireball formulas are absolutely safe to drink.”

The Food and Drug Administration has deemed propylene glycol as “generally recognized as safe” for use in food products, up to 50 grams per kilogram. The whiskey made by Fireball has less than 1/8 the amount of propylene glycol allowed by FDA regulations, a spokeswoman pointed out.

The European formula for Fireball has even less: under one gram per kilogram of propylene glycol.

“Propylene glycol (PG) is a regularly used and perfectly safe flavoring ingredient. PG has been used in more than 4,000 food, beverage, pharmaceutical and cosmetic products for more than 50 years. Most people consume PG every day in soft drinks, sweeteners,” the spokeswoman said.

Fireball Cinnamon Whiskey is manufactured by Sazerac, an alcoholic beverage company based in Metairie, La.