Aerosil

Aerosil, also known as silica foam or pyrogenic silica, is amorphous silica that is light and compact.
Due to its low weight and specific structure, it is added as a filler and a volumetric compound, increasing viscosity.
Uses of Erosil include

Silicone Elastomer Filler

Viscosity regulator in colors, coatings, printing inks, adhesives and polyester resins

Battery acid gel

Fill travertine pores

Used in the manufacture of composites and fiberglass

It is also used in the manufacture of cosmetics for the specific purpose of scattering light.

Fumed silica (Aerosil) is not included in the list of carcinogens, but due to its fineness and small size, it easily enters the air, causing burning if it enters the respiratory tract.