Airports strictly avoid using traditional rock salt (sodium chloride) on runways and taxiways because it is highly corrosive to aircraft aluminum and engine components. Instead, they use specialized chemical de-icers that are "aircraft-friendly" and meet rigorous SAE standards (like AMS 1435). The most common liquid de-icer is Potassium Acetate, which is effective at melting ice quickly and works at temperatures as low as -75°F. For solid applications, airports often use Sodium Formate or Sodium Acetate pellets, which provide a "holdover" effect to prevent new ice from forming. These chemicals are biodegradable and less harmful to the surrounding soil and water than salt. For the aircraft themselves, a heated mixture of Propylene Glycol and water (Type I, II, or IV fluid) is sprayed onto the wings and fuselage to remove frost and prevent ice buildup during takeoff, which is a critical safety procedure that prevents aerodynamic stalls in wintry conditions.