More recently, Fireball whiskey was recalled in a few countries for high levels of propylene glycol. https://www.huffpost.com/entry/fireball-whiskey-recall_n_606... Note that it had the same levels in the USA but was not recalled because our standards are laxer. Still, it's unlikely to to kill you.
Propylene glycol is a food additive. It is also used in "safe" anti freeze. It is not the same as Ethylene glycol which is common automotive anti freeze and very toxic.
It's also one of the primary ingredients in most e-cigarette vape fluids too, and used in fog machines for the same reason.