Apply a drop of bleach solution to a hidden part of the fabric. after 1 minute, blot dry and look for a color change. no change means you’re good to go.
How to Get Sweat Stains Out of Armpits
Do your white shirts have armpit stains? Learn how to remove pit and sweat stains from the armpits of your white shirts and other clothing and fabrics.
Rub in a bit of liquid laundry detergent to pre-treat. Wait 5 minutes.
Wash on the hottest recommended water setting along with your favorite detergent. Make those clothes sweat!
Air-dry to help prevent any remaining stain from changing colors.