Summary of ARCH CHEMICALS INC

Results of Operations and Financial Condition, Financial Statements and Exhibi

ITEM 2.02. RESULTS OF OPERATIONS AND FINANCIAL CONDITION

On November 10, 2008, Arch Chemicals, Inc. (the "Company") released the results of operations and financial condition for the three and nine months ended September 30, 2008. Attached as Exhibit 99, and incorporated herein by reference, is a copy of the Company's earnings press release dated November 10, 2008.

Included in Exhibit 99 are references to the Company's income and earnings per share from continuing operations which, in some cases, as noted in such Exhibit, exclude the effects of the restructuring, the impact of the change in the U.K. tax rate related to the Company's U.K. pension plans and the impact of the increase in the Company's stock price on compensation expense related to the Company's share-based compensation programs recorded during the three months ended September 30, 2007. Additionally, there are references to the Company's 2008 full year estimate of diluted income per share from continuing operations which in some cases as noted in such Exhibit, exclude the effects of a pension settlement associated with severance recorded in 2007. Reconciliations of these non-GAAP financial measures to what the Company believes is the most directly comparable U.S. GAAP financial measures are provided in such Exhibit. The Company believes that these non-GAAP financial measures provide comparative information to the earnings guidance that was provided on July 31, 2008 by the Company as well as comparison of results to prior year and therefore are useful to the investment community.