Yellow Silica Gel can appear as beads, in granular, or powder, and is typically tough and hard, slightly resembling glass. Using silica gels with indicating abilities allow the user to know when the product has reached its adsorption capacity and will no longer continue adsorbing water. Yellow silica gel has been enhanced with phenolphthalein to allow for color indication. This product is sometimes used in place of blue and is considered very safe for use around food or medicine.