Potassium permanganate comes as deep purple crystal. It is used to treat water and remove stains. Handling potassium permanganate without gloves will leave brown stains on your skin. Permanganate is not water-soluble, so the stains cannot be washed out. Fortunately, the stains can be removed a couple of ways with common household products.
Rinse the stained item with a mild acid, such and lemon juice or vinegar. Multiple rinsings may be needed to fully remove the stain.
Apply a paste made from equal parts cream of tartar and hydrogen peroxide directly to the stain. Note that hydrogen peroxide will bleach clothing. Test the paste on a small section before applying to a larger area.
Use products containing sodium metabisulphite to neutralise potassium permanganate in commercial or industrial environments.
Potassium permanganate can be fatal if swallowed. Potassium permanganate can cause permanent staining.