Hydrogen peroxide

The 3-percent solution of hydrogen peroxide widely sold as a health aid is an oxidizer that can be used as a spot remover on most fabrics, even silks, wools and acetates that would be damaged by the chlorine in bleach. It does a good job as a laundry pre-treating agent, removing blood stains and scorch marks. As always, test the fabric in an inconspicuous area before attempting to remove the spot.

Peroxide (H₂O₂) is unstable — it has a tendency to lose one oxygen molecule over time, eventually becoming all water (H₂O). So pay attention to expiration dates and don’t buy too much of it at one time, or it will lose its effectiveness for any purpose.

Reference:

 

Jeff Bredenberg, editor, in Clean It Fast, Clean It Right: The Ultimate Guide to Making Everything You Own Sparkle & Shine.