Sodium persulfate (disodium peroxodisulfate, brief SPS), a stable salt of peroxodisulfuric acid, is a strong, yet easy to dose oxidant and an excellent radical source in aqueous media. RheinPerChemie serves the product in the form of color- and odorless crystalline powders. Due to its high purity and low moisture content, SPS from RheinPerChemie is storage-stable and can be handled safely. Occasionally, SPS tends to form lumps or cake when stored under ambient conditions. This behavior can be suppressed by small amounts of special silica additives. Sodium persulfate is highly water-soluble. Aqueous solutions react slightly acidic and are less storage-stable than the anhydrous solid.

In consequence of its high oxidation potential, SPS can decompose when subjected to adverse conditions. The product itself is not flammable, but oxidizing.