This is one pound of ammonium persulfate which is also known as ammonium peroxydisulfate. A white crystalline solid having a density of 1.98. Uses include - oxidizing agent, bleaching agent, photography, etchant for printed circuit boards, etching copper, electroplating, preserving food, and deodorizing. This material is shipped in compliance with USPS Publication 52 as an ORM-D. Shipping .90.