potassium permanganate is used as an oxidizing agent. it also is used in disinfectants and in deodorizers. it can be used to make many different kinds of chemicals. in waste water treatment, it is used to get rid of hydrogen sulfide, a stinky toxic gas. in analytical chemistry, an accurate concentration of kmno4 is sometimes used to see how much of a certain reducing agent is in the titration. in a related way, it is used as a reagent for wood pulp. mixing potassium permanganate and formaldehyde makes a mild tear gas.