Indicating DRIERITE is anhydrous calcium sulfate desiccant which turns from blue to pink when saturated. DRIERITE indicating desiccant can be easily be regenerated repeatedly for reuse by simply heating in an oven. Re-dried desiccant is ready for use when the materials turns back from pink to blue. Desiccant material is pH neutral and constant in volume. Desiccant is also chemically inert except toward water. DRIERITE is insoluble in organic liquids and refrigerants, non-disintegrating, non-wetting, non-toxic, non-corrosive and non-channeling. DRIERITE desiccant is generally recognized as safe (GRAS) by the FDA. Material is not regulated by OSHA. Typical analysis >99.5% CaS04. Mesh Size: 4. Drierite Item #: 23001.