ARJ Arch Chemicals

Monday, August 8, 2005 1:00 p.m. Eastern Time A conference call to review second quarter results will be held on Monday, August 8, 2005, at 1:00 p.m. (ET) by Michael E. Campbell, Chairman, President and CEO, and Louis S. Massimo, Executive Vice President and CFO. Prepared remarks will take about 20 minutes and will be followed by a question and answer period. Financial and segment information will be released Monday morning, August 8, before the market opens. The release will be available on First Call, Business Wire and Dow Jones News Service. If you wish to participate, please call (800) 591-6930, passcode 71153293, at least ten minutes before the call is scheduled to begin. From outside the U.S., please call (617) 614-4908, passcode 71153293. The live web cast of the call can be accessed on the home page of the Company's Web site: http://www.archchemicals.com; it will be Windows Media Player and RealPlayer compatible. In the event you are unable to participate in the conference call, a replay will be available from 3:00 p.m. on Monday, August 8, until 6:00 p.m. (ET) on Monday, August 15. The replay number is (888) 286-8010, passcode 23781839; from outside the U.S., please call (617) 801-6888, passcode 23781839. Headquartered in Norwalk, CT, Arch Chemicals, Inc. (NYSE:ARJ) is a global specialty chemicals company with more than $1 billion in annual sales. Arch and its subsidiaries have leadership positions in the Treatment and Performance Products segments, where they serve leading customers with forward-looking solutions to meet their chemical needs. Together with its subsidiaries, Arch has 2,700 employees and manufacturing facilities in North America, South America, Europe, Asia and Africa. For more information, visit the Company's Web site at http://www.archchemicals.com.