Chlorine is a chemical building-block used in everything from swimming pools to plastic tents to paper towels.
In 1894, a process was devised to produce chlorine by pumping a saltwater solution (brine) through a vat of mercury, or "mercury-cell," that catalyzes an electrolytic chemical reaction.
Newer technologies that do not use mercury have been developed and have been in use since the 1980s. This newer technology is up to 37 percent more energy efficient, can increase operating capacity by up to 80 percent and some factories that have converted have earned back their investment within five years.
More than 115 factories have converted from mercury-based to mercury-free technology over the decades, yet a number of plants around the world continue to use the unnecessary outdated technology, releasing tons of mercury into our environment each year.