Your initial reaction is: Great. You are feeling better about the choice you made. Eighty percent fat free! Seventy percent sugar free! Your heart and waistline will thank you, and you are certain: this must be good for you.

　　Just when you stop for a moment and start thinking about it, you might wonder … what happened to the other 30 percent?

　　The food industry started it. And, whatever works successfully in one market, others are sure to copy. Unfortunately the paper industry is no exception.

　　Sooner or later marketing in all its glory takes over, and the issues get more blurry and confusing for everyone. How can a paper be elemental and process chlorine-free?

　　But don’t despair. Help is on its way.

　　The brighter the …

　　For years, the trend in the paper industry has been towards whiter and brighter papers. The original AF&PA grade chart (the one that used to determine No. 1, No. 2, etc., grades) ended with a brightness of 87.9, but now, papers with 95 - 98 brightness are common.

　　To achieve these wonderful brightness levels, pulp mills used to use chlorine gas in the bleaching process. But, the chlorine molecules combined with organic molecules in the wood fibers created cancer-causing dioxins in the environment.

　　The good news is that virtually all North American mills have converted to an at least "elemental chlorine-free" processes. The ECF process uses chlorine derivatives, primarily chlorine dioxide, instead of elemental chlorine gas. This is better, but not perfect.

　　Three free chlorines

　　There are three terms commonly used in the papermaking process for bleaching paper:

　　Totally Chlorine-Free means that 100 percent virgin fiber (including virgin tree-free fiber) is unbleached or bleached with non-chlorine compounds. It may also include wood or alternative fibers, such as kenaf.

　　Processed Chlorine-Free indicates that the recycled fiber in the sheet is unbleached or bleached with non-chlorine compounds. PCF papers are not considered totally chlorine-free because of the unknown bleaching process of the original fibers that have now been recycled. Any virgin fibers in a PCF sheet must be TCF.

　　Elemental Chlorine-Free indicates virgin or recycled fiber that is bleached with chlorine dioxide or other chlorine compounds. This process significantly reduces hazardous dioxins, but does not completely eliminate them.

　　30 percent sugar free

　　In an effort to promote their environmental and chlorine consciousness, some mills have started to draw attention to the PCF portion of their papers, by pointing out that their papers are PCF and ECF.

　　In those cases, the recycled portion of the pulp is usually PCF, while the virgin portion is ECF.

　　And the mills have to be specific about this. “A paper can only be either or! If there is any ECF pulp involved in the making of this paper, it cannot just be called PCF,” says Archie Beaton, executive director of the Chlorine Free Products Association. Think of it as the weakest link.

　　Just think about our soft drinks again. You cannot claim it to be completely sugar free, if 30 percent of it is made with the sweet stuff.

　　How to spec

　　The best approach to keeping it all straight is determining your green preferences and goals. As with much of life, priorities and compromises rule the day.

　　If it’s important to you or your client that the paper is made from recycled fibers, then realize the best you can do in the chlorine-free department is a sheet that is completely PCF.

　　This does not mean it has to be 100 percent recycled. It could also be a sheet that is made from recycled pulp, that is PCF, and the virgin portion of the pulp is TCF.

[时间：2007-12-14  作者：Sabine Lenz  来源：信息中心]