October 28, 2003,

Crompton Corporation of Middlebury, CT (NYSE: CK) and the Plant and Material Protection division of Janssen Pharmaceutica, N.V. of Beerse, Belgium have entered a long-term cooperative research understanding to develop the novel fungicide and algaecide bethoxazin.

Bethoxazin is a non-halogenated, non-metallic biocidal compound originally discovered in the synthesis and screening program of the Crompton Corporation Crop Protection Division.  Bethoxazin has been extensively tested to show excellent control of mold and algae in a variety of situations.

The agreement calls for Janssen Pharmaceutica to continue development of bethoxazin under the Crompton patent for material preservation use in all areas including paints, coatings, cooling liquids, metal working fluids, lubricants, leather, textiles and wood.

“This is an example of our commitment to cooperative development for the new chemistry generated by the Crompton discovery and research program,” said Alfred Ingulli, executive vice president of Crompton’s Crop Protection business.  “This agreement offers the best opportunity to reach market potential by offering consumers better solutions through cooperative research efforts that take advantage of the core business capabilities of Crompton and the Plant and Material Protection Division of Janssen Pharmaceutica N.V.”

Crompton Corporation, with annual sales from continuing operations of approximately $2.1 billion, is a producer and marketer of specialty chemicals and polymer products and equipment providing the solutions, service and value our customers need to succeed.