What Are the Causes of Yellow Underarm Stains?

• The chemicals in antiperspirants cause underarm stains on clothing. man's solid deodorant image by Jim Mills from Fotolia.com

  Underarm stains can be permanent, unsightly areas of discoloration on a shirt. Although most people commonly associate these stains with sweat, they're actually caused by antiperspirant use. Unlike deodorants, which reduce or eliminate odor, antiperspirants only decrease underarm sweating. They employ chemicals, usually metallic salts, that reduce perspiration by blocking sweat ducts. Yellow underarm stains occur when antiperspirants come into contact with clothing.

Cause of Underarm Stains

• The acidic composition of antiperspirants causes the color shift in clothing that results in yellow underarm stains. The chemical ingredients in these products, such as aluminium zirconium tetrachlorohydrex gly, react with sweat and produce a stiffening and staining on the underarm area of shirts. Gel and roll-on products transfer easily to clothing owing to their water content and cause more staining than solid antiperspirants, based on information from Sweat Solutions.

Prevention

• Though most people find it impractical to completely disregard antiperspirant use, there are ways to prevent underarm stains from forming while using such products. After applying a thin layer of antiperspirant, you should allow it to dry completely before putting on clothing that comes into contact with that area. Bacteria present in the underarms can increase sweating and the likelihood of underarm stains. Bathing daily can reduce the growth of the types of bacteria that increase sweating and produce body odor, according to Quality Health. Additionally, you should always shower after exercising, as sweat increases after physical activity. The bacteria also react with hair, so trimming or removing underarm hair can decrease their growth. Anxiety can cause perspiration, so utilizing relaxation techniques, such as meditation, may prevent sweat triggered by emotion. Relaxation techniques can also reduce stress, which also causes perspiration.

Stain Removal

• It is easier to remove yellow underarm stains if the affected clothing is treated before you wash and dry it. The same chemicals in antiperspirant that cause underarm stains can permanently lock in the stains if the clothing is washed in hot or warm water without pretreatment. Rinse the article of clothing in cold water before washing it in the warmest water allowed by the clothing label, suggests Sweat Solutions. Hydrogen peroxide may also work as an underarm stain pretreatment, although it may not be as effective as cold water. Commercial laundry pretreatment products can actually worsen underarm stains.