ABSTRACT
Greenpeace and other environmental organizations have called for the phasing out of chlorine and the products made using it.1 Other groups, including the Society of Toxicology, American Medical Association (AMA), the American Chemical Society (ACS),2 Michigan Environmental Science Board,3 American Chemical Council (formerly Chemical Manufactur ers Association) Chemical Manufacturers Association Chlorine Chemistry Council,4 American Industrial Health Council,5 and United Kingdom (U.K.) Chemical Industries Association,6 have said that this is unnecessary. The last calls the request the result of chlorophobia. It points out that there are about 1500 natural chlorine-containing compounds, including epibatidine (3.1 Schematic), a painkiller 200 times more powerful than morphine, which is used by an Ecuadorian tree frog for defense. It is a highly poisonous nerve toxin used by natives in their blowpipes. Gribble7 has also called attention to about 2000 natural chlorine compounds, including many from marine algae. (Marine algae contain vanadium haloperoxidases that catalyze halogenations.8) One group of fungi, basidomycetes, even produce chloromethane as well as chlorinated aromatic compounds.9 Methyl bromide is emitted by Brassica plants (in the mustard family).10 Bromophenols are part of the prized avor of shrimp.11 These natural halogen compounds include at least two that are essential for human life, hydrochloric acid in the stomach and thyroxine (3.2 Schematic) in the thyroid gland.
