Spectrum Chemical manufactures and distributes fine chemicals with quality you can count on including those with CAS number 27503-81-7, Whether you call it Ensulizole, 2-Phenylbenzimidazole-5-sulfonic Acid or Phenylbenzimidazole Sulfonic Acid you can be assured the Ensulizole products offered by Spectrum, meet or exceed the grade requirements or specifications for each individual product.