De-icing runways

What do airports use on runways to de-ice them? They cannot use salt, due to the corrosion, and sand is used sparingly as it's too gritty for engines to suck up.
Instead, they use urea on aircraft movement areas and aprons, a.k.a. cow pee.
Okay, maybe it's a synthetic pig urine extract, as well as another solid de-icers called Sodium Acetate and Sodium Formate.
But it's still pee.