Ability of pyrogenic silica to cause thickening of the liquids allows to vary their viscosity in a wide range and thereby to stabilize dispersions and emulsions, which is particularly important for production of various plastics.
Use of pyrogenic silica in production of polyvinylchloride mixtures provides for regulation of the working viscosity of the mixtures.

As an additive to plastic the pyrogenic silica is used in the form of the following grades: FUMISIL200, FUMISIL300, FUMISIL M170, and FUMISIL M120.