Type IV de/anti-icing fluids are manufactured and qualified to AMS 1428 / ISO 11078 specifications. Type IV fluids offer maximum anti-icing holdover protection, but can also be used for de-icing purposes.
Similar to Type II fluids, Type IV fluids can be used in a variety of ways:
- Unheated and undiluted (or diluted) for anti-icing
- Heated and undiluted for de-icing / anti-icing as a one step process
- Diluted with water and heated for de-icing / anti-icing as a one step process
- Diluted with water and heated as the de-icing stage in a two-step process, when used with the unheated and undiluted fluid as step two.