ARJ Arch Chemicals

The Arch Chemicals, Inc. Board of Directors on October 28, 2010 declared a quarterly dividend of 20-cents on each share of Arch Chemicals (NYSE:ARJ) common stock. The dividend is payable on December 15, 2010 to shareholders of record at the close of business on November 15, 2010.

Headquartered in Norwalk, Connecticut (USA), Arch Chemicals, Inc. is a global Biocides company with annual sales of over $1 billion.  Arch and its subsidiaries provide innovative, chemistry-based and related solutions to selectively destroy and control the growth of harmful microbes.  The Company's concentration is in water treatment, hair and skin care products, wood treatment, preservation and protection applications such as for paints and building products and health and hygiene applications.  Arch Chemicals operates in two segments:  Biocides Products and Performance Products.  Together with its subsidiaries, Arch has approximately 2,800 employees and manufacturing and customer-support facilities in North and South America, Europe, Asia, Australia and Africa.

CONTACT:  Arch Chemicals, Inc.
          Investor contact: 
          Mark E. Faford
            (203) 229-3820
             mefaford@archchemicals.com
          Press contact: 
          Dale N. Walter
            (203) 229-3033
            dnwalter@archchemicals.com