A small amount of ferric oxide is added to a solution of oxalic acid, a commonly used cleaning and bleaching agent. Once the rust is dissolved, potassium carbonate is slowly added to the solution ...

However, the powder may not be as harmless as you might think ... This is because the ingredient that makes the cleaner so effective, oxalic acid, is corrosive. Though the oxalic acid used in Bar ...

On its own, oxalic acid is recommended for removing water stains ... BKF's two main formulas are its classic powder and cream ...