One problem associated with making paper is the
chlorine (Cl2) and chlorine compounds (such as chlorine
dioxide, ClO2), used to bleach about 40% of the world’s pulp for making paper. These compounds
are corrosive to processing equipment, hazardous for
workers, hard to recover and reuse, and harmful when
released into the environment. A growing number of
paper mills (mostly in the European Union) are replacing
chlorine-based bleaching chemicals with chemicals
such as hydrogen peroxide (H2O2) or oxygen (O2).