Ah, I see. http://en.wikipedia.org/wiki/Sodium_hydroxide#Manufacture http://en.wikipedia.org/wiki/Sodium_hydroxide#Manufacture Wikipedia claims "the membrane

Ah, I see. http://en.wikipedia.org/wiki/Sodium_hydroxide#Manufacture http://en.wikipedia.org/wiki/Sodium_hydroxide#Manufacture Wikipedia claims "the membrane cell process is economically the most viable", which does not use mercury. Also, as shown in my previous links, chloralkali plants (which make caustic soda) pollute a significant amount of mercury (needlessly, in my opinion).