Recycling paper that comes from magazines, newspapers and other printed material involves a process called de-inking, when soaps or surfactants are used to remove ink from the fiber. Surfactants can contain one or more chemical components, including sodium hydroxide and sodium silicate.
Virgin and recycled papers undergo a bleaching process during their pulp stage. Some chlorinated compounds, also called dioxins, are carcinogenic and can be used during the bleaching process, despite their harmful effects if released in the environment. This proves that not all recycled papers are environmentally friendly. Knowing the chemicals used during the recycling process is the best way of avoiding recycled papers that have negative effects on the environment. The symbol ECF, which stands for Elemental Chlorine Free, indicates that no chlorine gas was used. But, chlorine dioxide and other chlorinated compounds can still be used during the bleaching process of ECF papers.
Oxygen, enzymes and hydrogen peroxide are environmentally friendly alternatives to chlorinated compounds, during the whitening process. Following the de-inking process, the recycled pulp has a brightness of about 50 percent. After the bleaching process, which often uses hydrogen peroxide, brightness of the paper can be above 85 percent. As most of the recovered paper is already white, there is less emphasis on bleaching in the production of recycled papers, compared to virgin pulps.