Environmental
Paper Definitions
About Bleaching
The Paper Industry
Standards and
Environmental Logos  |
About
Bleaching |
lmost all virgin paper and the 50% virgin fibre in most recycled papers are bleached with either chlorine gas or chlorine compounds (most notably chlorine dioxide). Although some manufacturers are starting to offer non-chlorine bleached alternatives, chlorine bleaching remains the main method of whitening paper in North America.
Bleaching is done to remove or modify the lignin in wood pulp and to create desired levels of whiteness in paper. Chlorine in the bleaching process combines with organic molecules in the wood to form an array of toxic compounds called organochlorines. Dioxin is the best known of these compounds, but chlorine bleaching can create over 1000 different organo-chlorines of which only about 300 have been identified and tested for environmental effect. Many chemical substances that have been banned in recent years (including DDT, PCB, and chlordane) are organochlorines.
There are a variety of alternatives to chlorine bleaching, including oxygen and hydrogen peroxide. These methods do not produce organo-chlorines. Both recycled and non-recycled papers can be whitened without chlorine. The phrase "elemental chlorine free" which is used by some manufacturers is misleading to merchants and customers because even though the words "chlorine- free" are used in the labelling, it means only that chlorine-dioxide (or other chlorinated compounds) is used instead of elemental chlorine gas. While this does reduce chlorine related pollution, it is not chlorine free and does produce organo-chlorines.
Unbleached and hydrogen peroxide bleached papers are the best environmental options. Several unbleached printing and copy papers are now available. As has been demonstrated, in promoting more use and production of recycled paper, consumer awareness and demand is the best way of encouraging manufacturers to make positive environmental changes.
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