Bleach

There are many parallels in the histories of pulp and textile bleaching because early paper was commonly made from rags. In the 1700s sunlight was used to bleach paper. After 1800, bleaching powder was used to whiten the rags used to make paper. In the early 1800s wood came into use as a source of paper and calcium hypochlorite was used as the bleaching agent.

After World War I chlorine bleaching came into use in paper production because compressed chlorine gas became available. By the 1950s, chlorine dioxide had become the principal pulp bleaching agent. More recently, peroxygens such as hydrogen peroxide have been used.