Bronopol is a water soluble, broad spectrum preservative which is highly effective against both gram-positive and gram-negative bacteria. It is poorly soluble in non-polar solvents but shows a high affinity for polar organic solvents. And it is supplied as crystals or crystalline powder, which may vary from white to pale yellow in colour depending on the grade of material being offered. Bronopol is used as a biocide and preservative in process fluids, paper mills, personal-care products, metal-working fluids, fuel/oil storage tanks, and water-based paints, inks, and adhesives. It reacts with some metals, amines and alkaline compounds. But it is stable in acidic media. It retains its activity in anionic, cationic, and nonionic systems. It is typically used at concentrations of less than 0.1%, which provides cost effective preservation, even against Pseudomonas aeruginosa. It is very stable in acid media and is recommended for use as the primary preservative in neutral or acidic formulas.