In the US we have 4 different types of Deicing and Anti-Icing Fluids.

Type I Fluid: Applied hot to raise the temperature of the aircaft skin in addition to melting the accumulated ice/snow. It’s a thin fluid so it runs off quickly so its anti-icing capability is low. Mixture ratio (glycol to water) is adjusted to keep the freezing point of the fluid below the OAT (outside air temperature). I ususally see it offered at 50/50 but a few weeks ago it was applied at 25%. The maximum ratio is 80%. Type I is used as a deicer and offers little if no anti-icing protection.

Type II Fluid: I don’t know if this is even offered or used by anyone anymore. It’s a thick fluid intented for aircraft with high takeoff speeds.

Type III Fluid: A cross between Type I and Type IV. It can be applied heated and offers the deicing capability found in Type I as well as anti-icing protection found in Type IV (but not as much protection). It’s capable of being heated and applied using Type I application systems.

Type IV Fluid: A thick fluid used as an anti-icing protection. After an application of Type I to remove any accumulated ice/snow Type IV is applied to protect against any further accumulation. The time of protection is determined using charts and take into account the Outside Air Temperature, brand of fluid, mixture ratio, type of precipitation and rated strength of that precipitation. Type IV offers the longest Hold Over Times (precipitation protection) of the 4 fluid types.

The anti-icing fluids being thick fluids stick to the aircraft to extend their protection life but are designed to sheer from the aircraft skin before rotation and take any accumulated ice/snow with it.

Anti-Icing and Deicing fluids are either Ethylene Glycol or Propylene Glycol based.