Elemental Chlorine Free Pulp Mills
Despite trying to sell it as the "the worlds greenest pulp mill" (see ) Gunns proposal is for an Elemental Chlorine Free pulp mill.
Here is the semantic history of the term 'elemntal chlorine free from 
"In 1992, the BC government passed a Zero AOX law requiring mills to eliminate organochlorines such as dioxins from their effluent by 2002. Other jurisdictions passed similar legislation. The pulp in-dustry chose not to go the TCF route, opting instead to spend a great deal of money installing secondary treatment for effluent, which would capture more contaminants before they entered the aquatic environ-ment, and switching from bleaching with chorine gas (elemental chlorine) to chlorine dioxide.
Chlorine and pulp manufacturers funded a new organisation, the benignly named Alliance for Envi-ronmental Technology (AET), the main purpose of which was to promote chlorine dioxide as the most environmentally sound form of pulp bleaching. In response to public concerns about chlorine, mills bleaching with chlorine dioxide coined a new term — Elemental Chlorine Free (ECF) — and began referring to their product this way, sometimes even calling it chlorine free."
Why is the term ECF so misleading? Because as Joe Thornton explains in Pandora's Poison: Chlorine, Health and the New Environmental Strategy 'chlorine dioxide, the bleaching agent used by ECF pulp mills, reacts with water in the bleach plant to produce elemental chlorine (Cl2) and hypochlorous acid (HOCl), each of which then react with organic matter to produce organochlorines.'
The organochlorines in ECF pulp mill effluent include two of the deadliest chemicals know to man: dioxin and furan.
These chemicals are classed as Persistent Organic Pollutants (POPs) and are the subject of the Stockholm Convention. The Stockholm Convetion  came into force as international law on the 17th of May 2005 and was ratified by Australia on May 20th. The web site reads:
"The Stockholm Convention is a global treaty to protect human health and the environment from persistent organic pollutants (POPs). POPs are chemicals that remain intact in the environment for long periods, become widely distributed geographically, accumulate in the fatty tissue of living organisms and are toxic to humans and wildlife. POPs circulate globally and can cause damage wherever they travel. In implementing the Convention, Governments will take measures to eliminate or reduce the release of POPs into the environment."
Accodring to the US Environmental Protection Authority  there appears to be 'no' safe level of exposure to dioxin.