Olin was the first to produce high-purity caustic soda over 100 years ago, and we now use all three commercially available processes. Caustic soda is the sixth-most commonly produced chemical in the U.S., based on volume. After more than 100 years, Olin is nearly the industry leader in producing all three grades of caustic, including rayon, membrane and commercial. Seventy percent of our output is high-purity caustic soda.