Perspiration stains usually appear as yellow stains in the underarms and on the back, and may have a noticeable odor. Perspiration is composed of mainly water, but it also contains other substances, such as chloride salts, amino acids, and ammonium compounds. These substances can oxidize with the heat of the drying cycle or the heat of pressing, causing the stains to turn yellow. Perspiration begins as acidic substance but later decomposes to an alkaline condition. Silk is very susceptible to becoming discolored by alkaline substances. The chloride salts in perspiration can weaken silk fibers, resulting in the development of holes over time.
The odor and staining from perspiration may not be removed in the drycleaning process. It may be necessary to treat the area locally with mildly acidic stain removal agents or tannin formulas. If the staining is extensive or does not respond to the milder stain removal agents, it may be necessary to wetclean the item in a bath containing hydrogen peroxide.
The bath should contain two to four ounces of three percent hydrogen peroxide per gallon of water. Hydrogen peroxide is a very slow acting bleach, so the item should be soaked somewhere between four to six hours.
Remember to always test for colorfastness before using any bleaching agent, as a color loss or change in color may occur. Because some slight change in texture or slight shrinkage may occur during this process, you may want to advise customers of the risks of this procedure.
DLI's Encyclopedia of Drycleaning Online features thousands of garments about all things drycleaning and is included as part of Standard, Gold, Premier or International memberships. Here are some bulletins to help further your understanding of this issue:
- Textile Analysis Bulletin Service (TABS) No. 378: Perspiration Stains
- Technical Operating Information (TOI) No. 700: Stain Removal 101, Part 1: Fats, Oils, Greases
- Technical Operating Information (TOI) No. 702: Stain Removal 101, Part 3: Animal & Dye Stains
- Technical Operating Information (TOI) No. 626: Deodorants and Antiperspirants
- Customer Service (CS) No. 16: How Often Should You Clean Your Clothes?