We are the leading & specialized manufacturer for Borax decahydrate in China, and our Borax has GMP certificate.it conforms to BP2007/USP31 Borax Certificate: GMP CAS:1303-96-4SPCS:CP2010/USP31/BP2009Packaging:40kg/DrumCharacters:A white, crystalline powder, colourless crystals or crystalline masses, efflorescent, soluble in water, very soluble in boiling water, freely soluble in glycerol.Assay99.0%103.0%Sulphates:50ppmAmmonium:10ppmArsenic:10ppmCalcium: 0.01%Iron: 0.003%Calcium: 0.01%Iron: 0.003%Carbonate and Bicarbonate: CompliesAppearance of solution: Complies