Sodium borate decahydrate,
Sodium tetraborate decahydrate,
Borax is used in laundry detergents and bleaches. It releases hydrogen peroxide when it reacts with water. Hydrogen peroxide acts as a bleach, and this action is aided by the alkaline solution also produced by the reaction.
Borax is a good buffer, helping to keep the acidity or alkalinity of a solution stable.
The boron (along with the oxygen and salt) in a borax solution helps to disinfect by killing bacteria and fungi.