Bleaching paper with elemental chlorine causes harmful AOX emissions in the aquatic environment. That is why all our papers are ECF products as a minimum standard, meaning they are bleached without elementary chlorine. The company’s volume of AOX lies within the BAT (Best Available Technique) range. This means technically and economically feasible environmental technology that is efficient and advanced and designed to reduce emissions and the impact on the environment as a whole.
NAUTILUS® ReFresh TRIOTEC, with TCF fibres in the outer layers and 30% recycled fibres in the inner layer, and BIO TOP 3® are our TCF (totally chlorine free) products, which are bleached without the use of any chlorine. Instead they are whitened using oxygen and hydrogen peroxide.
ECF (elemental chlorine free) = ECF bleaching is a bleaching sequence without the use of elemental chlorine. In ECF bleaching, chlorine dioxide is usually the main bleaching agent. Chlorine dioxide has the highest selectivity among technical bleaching chemicals. To minimize the environmental impact of the bleaching process the ECF process is usually combined with bleaching stages involving oxygen, hot acid, or ozone.
TCF (totally chlorine free) = TCF bleaching is carried out without any chemicals containing chlorine, thereby avoiding the generation of organically-bound chlorine in the pulp and waste water stream. In TCF bleaching, hydrogen peroxide together with ozone or peracetic acid are the most commonly used chemicals. Ozone is generated by means of energy intense silent electrical discharges in a stream of oxygen gas.
PCF (process chlorine free) = A bleaching process which entirely excludes the use of chlorine and chlorine dioxide. Nevertheless paper collected for recycling, which forms the basis of NAUTILUS® for example, may contain traces of chlorine substances. All recycled papers are produced using PCF.
Overall, it is accepted that TCF and ECF discharges cannot be separated on environmental grounds. It is now possible to demonstrate that the discharges to watercourses, from both ECF and TCF, are of no environmental concern.
Regarding the pulp itself, the ECF process has the advantage of a significantly higher ratio of finished fibre to wood. This is due to the fact that TCF bleaching is done with ozone, which is more corrosive chemical than chlorine dioxide.
Mondi offers TCF, ECF and PCF products in its portfolio in order to respond to our customers’ needs and preferences and we acknowledge both the advantages (zero AOX emissions) and disadvantages of TCF (lower yield).
* AOX: the sum of all absorbable organic halogens (chlorine, bromine and iodine compounds) in waste water.