Sometimes, people confuse propylene glycol with ethylene glycol. Their chemical structures are similar, and both are used in antifreeze, but they’re not the same.

Some Cold Stone Creamery ice cream flavors, 13 out of the 85 offered, contain trace amounts of propylene glycol. And just eight of Blue Bunny’s 106 ice creams list propylene glycol as an ingredient.

Propylene glycol is a synthetic food additive that belongs to the same chemical group as alcohol. It is a colorless, odorless, slightly syrupy liquid that is a bit thicker than water. It has ...