National Clothesline

Potassium permanganate is one of the most important bleaches for correcting staining when other bleaches do not work.

Many cleaners stay away from this bleach because they do not understand the chemicals necessary to neutralize it or how to use it. I have been using this bleach for many years and it has been invaluable for correcting many problems. I have used it for removing mildew on wool and silk because chlorine bleach could not be used. It can also be used as a last resort for dye, tannin and many inks.

Although it is the strongest oxidizing bleach on the spotting board, it is safer to use on wool and silk than sodium hypochlorite or chlorine bleach.

Potassium permanganate is termed oxidizing bleach because it adds oxygen to a fabric or stain. It is alkaline by nature but does not have the damaging effects that chlorine bleach has on fibers.

Potassium permanganate can be obtained from your supply houses in crystal form. A.L. Wilson Chemical sells the product called PermaGo, which is potassium permanganate in a liquid form that is ready to use.

I have seen potassium permanganate sold as a purifier for pools in a supermarket. These products are also found in liquid form.

When potassium permanganate starts to go bad, it looses some of its deep purple color and will turn brown.

Potassium permanganate can be applied to a stain with a Q-tip and it can also be used as bath bleach.

Potassium permanganate is accelerated by heat. Every 18°F rise in temperature doubles the chemical action. This means that heating with a steam gun or using very hot water can cause extreme acceleration.

When potassium permanganate contacts a fabric, it chemically changes to a brown color. This occurs because the bleach loses some of its ions. When an alkali contacts potassium permanganate it may also turn brown or green due to loss of manganese ions.

Proper neutralizing means changing or losing more of the ions, causing it to turn colorless. This can be done with acids or reducing bleaches.

Neutralizing potassium permanganate can be done with oxalic acid, sodium bisulphate or sodium hydrosulphite. Some of these will work better than others.

The best neutralizer for potassium permanganate is hydrogen peroxide plus acetic acid.

Potassium permanganate can be used on all fabrics, but color must be tested. Since white fabrics also contain fluorescent dyes, they, too, must be tested.

Use a Q-tip and apply to last traces of staining. Heat with the steam gun and then flush the area. Apply hydrogen peroxide and acetic acid as a neutralizer and flush the area.

Use warm water in a plastic bucket or pail. Do not use metal, iron or steel since this will accelerate and break down the bleach.

Add two ounces of potassium permanganate per gallon of water. Soak for ten minutes and then rinse garment thoroughly in clear water.

Make up a bath of a neutralizing agent such as a reducing bleach, oxalic acid or peroxide and acetic.

In my professional career as a garment analyst, I have been involved in the testing and development of new solvents, spotting and wetcleaning chemicals. In the development of wetcleaning, I tested the effectiveness of most wetcleaning chemicals. I have also tested the effectiveness of Pure Dry solvent and the results were published in the National Clothesline.

The testing of chemicals involves the effectiveness of the chemical to the following:

1. All types of staining.

2. Comparison of the chemical to other methods.

3. Safety of the chemical to all fabrics including wool and silk.

4. Ease that the chemical can be flushed and feathered.

5. Other uses for the chemical.

All testing is done in a live plant setting using prepared and live garments. A report on the effectiveness of the chemical will be issued to the company and a description of the testing results will be reported in my column.