HOW PAPER IS BLEACHED

Paper can be whitened, or bleached, in one of three ways:

• By using elemental chlorine. This is the most toxic method. It is prohibited in the European Union and its use has fallen off in much of the rest of the world: in 1990, 94.5% of bleached chemical pulp was processed this way and in 2005 only 10.5%.

• By using chlorine dioxide. Elemental Chlorine-Free (ECF) paper is the most common type of bleaching (84% of the global chemical pulp) in use today.

• Chlorine-free. In this case, hydrogen peroxide and sodium hydrosulphite (non-toxic chemicals) are used to bleach the pulp. This process is known as totally chlorine-free (TCF) in the case of virgin paper and partially chlorine-free (PCF) in the case of recycled paper.  This is still the least common method: 5.5% of global production. Recycled paper manufacturers tend to bleach without chlorine, or not to bleach at all.

Mostly, the paper industry considers the levels of pollution created by the ECF method low enough to consider it safe for the environment. Ecological organizations, part of the paper industry and some scientific studies argue otherwise.  In addition to avoiding the use of chlorine, the TCF method requires less water, this water can be reused in the process and it is easier (and uses less energy) to treat wastewater. The industry is reluctant to give up chlorine use, perhaps due to the costs of reconverting existing infrastructure, perhaps from pressure by the chemical industry.

According to PulpWatch, an initiative of the Environmental Paper Network and the Borealis Centre for Environment and Trade Research, in Mediterranean countries there are ten paper manufacturers, more specifically in Morocco, Portugal, Andorra, Spain and France. Of all these, only two use processes that are completely chlorine free (TCF or PCF); three use enhanced ECF techniques, and the other five continue to use traditional ECF technologies to whiten paper pulp.