Ethylene Glycol De/Anti-Ice Fluids remain in use, however it is not used as much because of environmental concerns. As far as I Know, the Isopropyl Alchohol/ethylene mixture (Type II
) is no longer in use commercially.
The modern De-ice fluids consist of Propylene Glycol, with type I typically a low viscosity fluid that is mixed with water, then heated to 170- 180 degrees F to melt snow and ice. it is orange in color.
is used full strength, and has a thickening agent to allow it to stick to the aircraft surfaces. It is green in color. The thickening agent has a shear factor, so that when the airspeed increases the fluids breaks down an runs off the wing. It is used during periods of freezing precip as a protective layer to prevent refreezing of the lifting surfaces. it is also very expensive, so the use of it is determned by whether the extra hold time is needed.
Hope this helps