Since many studies have pointed out ECF (Elemental Chlorine Free) as environmentally friendly with no harmful by-products and no specific toxicity of the resulting waste waters compared to TCF (Totally Chlorine Free); ECF bleaching is now considered all over the world as a Best Available Technology. Most of the incoming projects over the world are based on ECF bleaching and world ECF bleached pulp shate is still growing since it took the leadership in 1996. About 38 Mt of pulp was ECF bleached in 1997, 33 Mt was ECU (elemental chlorine used) bleached and 4 Mt was TCF bleached.Whatever wood species considered, transfer to ECF technology is easily achievable with respect to brightness and mechanical properties goals while minimising the quantity of organohalogenated by-products. Western Europe has almost completely turned to ECF and with the new Cluster Rules regulation (November 1997), NORTH AMERICA pulp mills still using chlorine are moving to ECF.To summarize we can conclude that moving to ECF technology is the best economical way to minimize pollutant and organohalogenated emissions with low investment cost and taking care of pulp properties. ECF is also the bleaching technology which will allow us to meet the year 2000 minimum mill effluent challenge.