Far from being America's household helper, and industry's best chemical friend, chlorine is something we should stop using right now. The chlorine controversy covers two separate but related issues. There's the issue concerning the use of chlorine to bleach paper. And there's the issue that has to do with using chlorine in household cleaning products. Let's look at paper bleaching first.
Chlorine is used by the paper industry for two purposes.
The first has to do with a substance called lignin. Lignin is the natural material a tree uses to hold its cellulose fibers together. Cellulose fibers are the raw material for paper. Because chlorine dissolves lignin, paper mills use it to rinse the lignin out of the wood pulp they need to make paper. Once the lignin is washed away, and the pulp is ready to be made into paper, chlorine is used again to make the paper white.