No matter what cleaning agents -- hydrogen peroxide included -- that you use to kill mold, unless you change the environmental conditions in which it arises, mold will keep coming back. When you kill and clean toxic mold with hydrogen peroxide, wear an appropriate safety-rated face mask and vinyl gloves, as mold spores can lead to illness.
As a fungi, mold spores are ever present in the air. When the conditions are right -- such as a damp, dark and humid environment -- mold grows, and mildew will thrive. As a fungi, bacteria and virus killer, pour 3 percent hydrogen peroxide solution or greater into a spray bottle and spray the affected area. Let the hydrogen peroxide do its work on the mold by sitting for at least 10 minutes. After 10 minutes, use a soft-bristled scrub brush to eliminate the mold and any stains. Wipe dry with a clean cloth. Other household cleaning agents that kill mold include undiluted vinegar sprayed onto the area or 1/4 tablespoon of baking soda combined with water and sprayed directly onto the mold or mildew.
Mold and Mildew Prevention
To keep mold and mildew from returning to a humid bathroom, add a ventilation fan sized to the room to remove the humid air during a bath or shower. After a shower, wipe down the walls with a towel or a squeegee to remove excess moisture. Let the fan run during a shower or bath and for a half-hour afterwards. When shower tiles are dry, add a sealant to the grout to help repel water and prevent future mold and mildew growth.