Para Nitro Toluene Ortho Sulphonic Acid is a white crystal wet cake. The Acid has the feature that 50% solution in water is clear and transparent. The Acid has purity of minimum 82% by nitrite value and insoluble of maximum 0.2%. The Para Nitro Toluene Ortho Sulphonic Acid has free acidity of 2% and purity by HPLC of minimum 99%.