Upasil® H and Upasil® WS are splash-resistant silica gels in bead form with a particle size of 2–5 mm. They are insoluble in almost all solvents, with the exception of strongly alkaline media and hydrofluoric acid.

When used at the air inlet of dryers, a pre-layer of Upasil® H or Upasil® WS extends the service life of the subsequent adsorbent bed. A small proportion of aluminium oxide gives the material the mechanical stability required for this application.

Compared to standard fine-pored gels such as Upasil® 20, Upasil® H exhibits a higher water absorption capacity in conditions of high humidity.