Sodium Hydroxide or Caustic Soda Lye or Solution is used in many industries, mostly as a strong chemical base in the manufacturing of pulp and paper, textiles, drinking water, soaps and detergents and as a drain cleaner. Physical Appearance : A clear colorless liquid, free from foreign matter. Relative Density at 40�°C: 1.485 % min. Sodium Hydroxide [as NaOH] : Min. 48.00 % Sodium Hydroxide (On Dry Basis) [as NaOH] : Min. 99.50% Sodium Carbonate [as Na2CO3]: Max. 00.20% Chlorides [as Cl]: Max. 0.015% Sulphate [as SO4]: Max. 0.015% Silicates [as SiO2] : Max. 00.010% Copper as [as Cu] : Max. 2.00 ppm Manganese [as Mn] : Max. 0.50 ppm Iron [as Fe] : Max 10.00 ppm