X0202 4 2006-02-28 0001072343 ARCH CHEMICALS INC ARJ 0001221040 MASSIMO LOUIS S C/O ARCH CHEMICALS 501 MERRITT 7 NORWALK CT 06851 0 1 0 0 Executive Vice President & CFO Common Stock $1 Par Value 2006-02-28 4 M 0 8000 A 9000 D Common Stock $1 Par Value 2006-02-28 4 D 0 8000 28.24 D 1000 D Common Stock $1 Par Value 4710.42 I By CEOP Trustee Phantom Stock 2006-02-28 4 M 0 8000 D 2008-12-31 2008-12-31 Common Stock 8000 0 D Phantom share units were granted on 1/30/2003 under the Arch Chemicals, Inc. 1999 Long Term Incentive Plan and are paid out in cash based on 2/28/06 fair market value as the financial measure (ROE) was reached by the company at the end of year three. No actual shares were issued and disposed of in making this cash payment. The figure shown represents shares of Arch Common Stock acquired on a periodic basis under the Contributing Employee Ownership Plan (CEOP), a tax conditioned plan, and held as of 02/28/2006 in the Arch Common Stock Fund of the CEOP, in transactions exempt under Rule 16b-3, and is based on information provided by the Plan Administrator . This security converts to common stock on a 1 for 1 basis. Joseph P. Lacerenza, Attorney in Fact 2006-03-01