along with, in the case of organochlorines, chlorine. Chlorine allows chemists to attach all kinds of other atoms to this skeleton, affecting for example the chemicals toxicity (desirable for pesticides) and solubility (desirable for solvents and plasticizers). But besides being industrially useful, such a chemical also tends to be persistent, bioaccumulative, chronically toxic, and frequently quite unpredictable. All of the dirty dozen of internationally banned persistent organic pollutants (POPs)including DDT, PCBs and dioxinare organochlorines. The problems with organochlorines are so systemic that many scientists and activists have called for the abandonment of case-bycase regulation of chemicals in favour of the phase-out of organochlorines as a class. This includes even the International Joint Commission on the Great Lakes, which saw organochlorines as the source of most of the lakes most serious environmental problems (Commoner, 1992). Numerous European countries have banned PVC for certain uses, and the worldwide green building movement has made total phase-out a top priority for eco-building. Some other classes of synthetic chemicals might also turn out to be as destructive as organochlorines, but organochlorines are the most pervasive chemicals in our chemicalized world, numbering over 11,000 in everyday commerce. In the words of W. Joseph Stearns, former Director of Chlorine Issues for Dow Chemical, chlorine has become the single most important ingredient in modern [industrial] chemistry (McGinn, 2000, p. 14). PVC is the single largest use of chlorine, consuming about 40 percent of total chlorine production, or approximately 16 million tons of chlorine per year worldwide. It is the second most common plastic and the most used plastic in construction. While it is