GREAT LAKES EXPANDS ANTIMONY OXIDE CAPACITY IN MEXICO

INDIANAPOLIS, INDIANA -May 19, 2003- Great Lakes Chemical Corporation (NYSE: GLK) today announced it has added a fifth antimony oxide production line at its Reynosa, Mexico, facility. Commercial production started in February 2003 and immediately boosted capacity by 20 percent.

The start up of the antimony oxide production line is consistent with Great Lakes’ strategy to remain at the leading edge of antimony production. This expansion increases the manufacturing output and flexibility at Reynosa and allows the company to meet market demand for its broad range of antimony oxide based synergists and flame retardants.

Productivity and quality enhancements were also achieved during the recent Class A Business Excellence and ISO 9001:2000 Quality Management System certification.

“These are achievements to be proud of,” stated Dr. Paul Bridges, Global Business Manager of Antimony and Fyrebloc® Products. ”Successful implementation of these procedures is a testament to the commitment and hard work of our employees at the Reynosa site and clearly demonstrates Great Lakes’ dedication to the highest standards of operational excellence. Class A Business Excellence and ISO 9001:2000 have enhanced operational efficiency at the site and simultaneously strengthened our ability to meet customers’ high standards of quality and service.”

Continued Bridges, “The addition of a fifth production line means that output and production flexibility have been boosted even further.”

The Great Lakes site was awarded Oliver Wight Class A certification, the highest status for operational excellence in sales and operations planning, following a rigorous assessment of internal processes and the implementation of quality and productivity improvements. Oliver Wight is a global management consulting and education firm that helps manufacturing organizations improve their planning and process control.

Great Lakes antimony trioxide, sold under the trade names TMS®, Timonox®, Trutint® and Microfine®, is used as a synergist, along with brominated flame retardants, in flame retardant polymer formulations widely used in electrical and electronics applications. Antimony trioxide is also an effective flame retardant in high performance PVC applications.

Through its Polymer Additives division, Great Lakes is the world’s leading producer of flame retardants. Its extensive line of products includes bromine-, phosphorus-, and antimony-based flame retardants and other synergists, as well as a full line of UV stabilizers, antioxidants, blends, and optical monomers. For more information about these product lines, please visit the Great Lakes Polymer Additives web site at www.pa.greatlakes.com.

This press release contains forward-looking statements involving risks and uncertainties that affect the company’s operations as discussed in Great Lakes Chemical Corporation’s Annual Report on Form 10-K filed with the Securities and Exchange Commission. Accordingly, there is no assurance the company’s expectations will be realized.

Janet Gilboy – Media (Europe and Asia)

+44 (0) 161 875 3229

Wendy Chance – Media (Americas)

+1 317 715 3027

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Great Lakes Chemical Corporation
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+1 (317) 715-30 00

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