Megh Rasayan is one of The Best PNTOSA Manufacturer, Exporter & Supplier India . Its chemical name is 4-Nitrotoluene-2-sulfonic acid. The CAS Number of Para Nitro Toluene Ortho Sulphonic Acid (PNT-OSA) is 121-03-09. It is a crystal with a gray or brown colour, and its empirical formula is C 7 H7NO5S. PNTOSA is acid used for intermediating dye stuff and the most common commercial name for...