Spectrum Chemical manufactures and distributes fine chemicals with quality you can count on including those with CAS number 136-40-3, Whether you call it Phenazopyridine Hydrochloride, 2 -6-Diamino-3-(phenylazo)pyridine Monohydrochloride or 3-Phenylazopyridine-2 -6-diyldiamine Hydrochloride you can be assured the Phenazopyridine Hydrochloride products offered by Spectrum, meet or exceed the grade requirements or specifications for each individual product.