Exhibit 99

News Release

_________________________

Arch Chemicals, Inc.

501 Merritt 7

P.O. Box 5204

Norwalk, CT 06856

Investor Contact: Mark E. Faford (203) 229-2654

Press Contact: Dale N. Walter (203) 229-3033

ARCH CHEMICALS PROVIDES UPDATE ON CONTRACT TO SUPPLY

HYDRAZINE PROPELLANTS TO THE U.S. GOVERNMENT

NORWALK, CT, April 14, 2005 -- Arch Chemicals, Inc. (NYSE:ARJ) has been notified by the U.S. Defense Energy Support Center (DESC) that a competing bidder has protested DESC’s March 29, 2005 award of a contract to the Company for the production, storage, distribution and handling of hydrazine propellants. Consequently, contract performance has been suspended pending final resolution of the protest.

Under this new, long-term contract, full-scale production was not scheduled to begin until 2007. Since there are no revenues and only minimal incremental costs associated with the awarding of this contract in the current year, the Company does not expect this action to have a significant impact on Arch’s financial performance in 2005.

The Company will assist the government in responding to any questions arising from this protest.

Headquartered in Norwalk, Connecticut, Arch Chemicals, Inc. 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 approximately 2,700 employees and manufacturing and customer-support facilities in North and South America, Europe, Asia and Africa.

Except for historical information contained herein, the information set forth in this communication may contain forward-looking statements that are based on management's beliefs, certain assumptions made by management and management's current expectations, outlook, estimates and projections about the markets and economy in which the Company and its various businesses operate. Words such as "anticipates," "believes," "estimates," "expects," "forecasts," "opines," "plans," "predicts," "projects," "should," "targets" and variations of such words and similar expressions are intended to identify such forward-looking statements. These statements are not guarantees of future performance and involve certain risks, uncertainties and assumptions ("Future Factors"), which are difficult to predict. Therefore, actual outcomes and results may differ materially from what is expected or forecasted in such forward-looking statements. The Company undertakes no obligation to update publicly any forward-looking statements, whether as a result of future events, new information or otherwise. Future Factors which could cause actual results to differ materially from those discussed include but are not limited to: general economic and business and market conditions; lack of moderate growth or recession in U.S. and European economies; increases in interest rates; economic conditions in Asia; worsening economic and political conditions in Venezuela; changes in foreign currencies against the U.S. dollar; customer acceptance of new products; efficacy of new technology; changes in U.S. laws and regulations; increased competitive and/or customer pressure; the Company's ability to maintain chemical price increases; higher-than-expected raw material costs for certain chemical product lines; an increase in anti-dumping duties on certain products; increased foreign competition in the calcium hypochlorite markets; unfavorable court, arbitration or jury decisions or tax matters; the supply/demand balance for the Company's products, including the impact of excess industry capacity; failure to achieve targeted cost-reduction programs; capital expenditures in excess of those scheduled; environmental costs in excess of those projected; the occurrence of unexpected manufacturing interruptions/outages at customer or company plants; reduction in expected government contract orders and/or the upholding of the protest of the award of the new U.S. government contract for hydrazine propellants; unfavorable weather conditions for swimming pool use; inability to expand sales in the professional pool dealer market; and gains or losses on derivative instruments.