When you flush the toilet, bleach is released into the bowl and begins to break down the waste. This process is known as disinfection. Bleach is a powerful disinfectant that kills most bacteria, viruses and fungi. It also breaks down organic matter such as hair, food and feces. Toilet paper is made from wood pulp and cellulose fibers. These materials are not affected by bleach. However, bleaching toilet paper can make it less absorbent and weaker.