Often the subject of environmental and public health concerns by association with chlorinated chemicals like polychlorinated biphenyls (PCBs) and chlorinated fluorocarbons (CFCs), chlorine (Cl) itself is a potentially serious hazard to workers and the environment. In Massachusetts, overall chlorine use is declining. However, in some industry sectors like high tech etching, gold refining, chlorinated rubber products, and water purification, its use is on the rise. In most applications safer substitutes for chlorine are available, but sometimes at a higher cost.
Chlorine poses the greatest potential for harm to human health through acute exposure.
Chlorine is extremely toxic to aquatic organisms; less than 0.1 micrograms of chlorine per liter of water has killed 50% of the exposed aquatic organisms.
Chlorine use dropped dramatically, by over 50%, between 1990 and 1996 in Massachusetts. The primary cause of the decline: Zeneca, Inc., ceased using 866,000 pounds of Cl due to cutbacks in production. Zeneca's dramatic reduction masked other increases in Cl use.