Exhibit 21 SUBSIDIARIES OF CROMPTON CORPORATION - 2003 Percentage of Voting Securities Owned Directly or Indirectly by State or Crompton Country of Corporation Organization 9056-0921 Quebec Inc. 100.0 Canada Agro ST Inc. 50.0 Delaware Assured Insurance Company 100.0 Vermont Baxenden Chemicals Limited 53.5 England Baxenden Scandinavia A.S. 53.5 Denmark Certis Europe B.V. 15.0 The Netherlands CK Witco Specialties Thailand Limited 100.0 Thailand CNK Chemical Realty Corporation 100.0 Pennsylvania Crompton & Knowles of Canada Limited 100.0 Canada Crompton & Knowles Receivables Corporation 100.0 Delaware Crompton (Uniroyal Chemical) Registrations Limited 100.0 England Crompton Agribusiness Pty. Limited 100.0 Australia Crompton B.V. 100.0 The Netherlands Crompton Chemical (Pty) Limited 100.0 South Africa Crompton Chemical S.r.l. 100.0 Italy Crompton Chemicals B.V. 100.0 The Netherlands Crompton Chimica S.r.l. 100.0 Italy Crompton Co./Cie 100.0 Canada Crompton Colors Incorporated 100.0 Delaware Crompton Corporation Limitada 100.0 Chile Crompton Corporation S.A. de C.V. 100.0 Mexico Crompton de Colombia Limitada 100.0 Colombia Crompton Espana S.L. 100.0 Spain Crompton Europe B.V. 100.0 The Netherlands Crompton Europe Financial Services Company 100.0 Delaware Crompton Europe Limited 100.0 Scotland Crompton European Holdings B.V. 100.0 The Netherlands Crompton Financial Holdings 100.0 Ireland Crompton GmbH 100.0 Germany Crompton Grand Banks Inc. 100.0 Canada Crompton Holding Corporation 100.0 Delaware Crompton Holding S.A de C.V. 100.0 Mexico Crompton Holdings B.V. 100.0 The Netherlands Crompton Holdings GmbH 100.0 Germany Crompton Inc. 100.0 Korea Crompton International Corporation 100.0 New Jersey Crompton International Sales Corporation 100.0 Barbados Crompton Investments S.A.S. 100.0 France Crompton Limited 100.0 Japan Crompton Limitada 100.0 Brazil Crompton LLC 100.0 Delaware Crompton Monochem, Inc. 100.0 Louisiana Crompton N.V. 100.0 Belgium Crompton Netherlands B.V. 100.0 The Netherlands Crompton Overseas B.V. 100.0 The Netherlands Crompton Quimica S.A.C.I 100.0 Argentina Crompton S.A. 100.0 France Crompton S.A. 100.0 Switzerland Crompton S.r.l. 100.0 Italy Crompton Sales Company, Inc. 100.0 Delaware Crompton Services B.V.B.A. 100.0 Belgium Crompton Servicios S.A. de C.V. 100.0 Mexico Crompton Specialties Asia Pacific Pte. Limited 100.0 Singapore Crompton Specialties GmbH 100.0 Germany Crompton Specialties Holding Company Limited 100.0 China-Hong Kong Crompton Specialties Limited 100.0 China-Hong Kong Crompton Specialties Limited 100.0 Taiwan Crompton Specialties Limited 92.0 Thailand Crompton Specialties Nanjing Company Limited 100.0 China-PRC Crompton Specialties Pte.Limited 100.0 Singapore Crompton Specialties Pty.Limited 100.0 Australia Crompton Specialties S.A. 100.0 Ecuador Crompton Specialties Sdn. Bhd. 100.0 Malaysia Crompton Specialties Shanghai Company Limited 100.0 China-PRC Crompton Technology B.V. 100.0 The Netherlands Crompton Vinyl Additives GmbH 100.0 Germany Crompton, Inc. 100.0 Philippines Crompton-CNCCC Danyang Chemical Company Limited 85.0 China-PRC D-S Brookes Limited 100.0 England Davis-Standard (Deutschland) GmbH 100.0 Germany Davis-Standard Corporation 100.0 Delaware Davis-Standard France S.A.R.L. 100.0 France Davis-Standard GmbH 100.0 Germany Davis-Standard Limited 100.0 England Enenco, Incorporated 50.0 New York Fasting Jonk N.V. 100.0 The Netherlands Firma W/K Witco EPA 50.0 The Netherlands GT Seed International Company 100.0 Texas GT Seed Treatment, Inc. 100.0 Minnesota Gustafson LLC 50.0 Delaware Gustafson Partnership 50.0 Canada Handelsmaatschappij Camphina N.V. 100.0 The Netherlands Herdillia Unimers Limited 8.0 India Industrias Gustafson S.A. de C.V. 50.0 Mexico Isofoam Limited 53.5 England Jonk B.V. 100.0 The Netherlands Kem Manufacturing Corporation 100.0 Georgia Lucia Kaarsen Fabriek N.V. 100.0 The Netherlands Monochem, Inc. 100.0 Louisiana Nanjing Crompton Shuguang Organosilicon Specialties Co., Ltd. 85.0 China-PRC Naugatuck Treatment Company 100.0 Connecticut Nerap Expeditie B.V. 100.0 The Netherlands NPC Services, Inc. 12.75 Louisiana PT Crompton Indonesia 100.0 Indonesia Rubicon LLC 50.0 Utah Trace Chemicals LLC 50.0 Delaware Unicorb Limited 100.0 England Uniroyal Chemical Company, Inc. 100.0 Delaware Uniroyal Chemical Company, Inc. 100.0 New Jersey Uniroyal Chemical Company Limited 100.0 Bahamas Uniroyal Chemical Company Limited (Delaware) 100.0 Delaware Uniroyal Chemical Export Limited 100.0 Delaware Uniroyal Chemical Leasing Company,Inc. 100.0 Delaware Uniroyal Chemical Mexico S.A. de C.V. 100.0 Mexico Uniroyal Chemical S.A 100.0 Spain Uniroyal Chemical S.A.R.L. 100.0 Switzerland Uniroyal Chemical Taiwan Limited 80.0 Taiwan Weber City Road LLC 100.0 Louisiana Witco Corporation UK Limited 100.0 England Witco Europe Investment Partners 100.0 Delaware Witco Investment Holdings B.V. 100.0 The Netherlands Witco Investments B.V. 100.0 The Netherlands Witco Ireland Investment Company Limited 100.0 Ireland Witco Polymers and Resins B.V. 100.0 The Netherlands Witco Warmtekracht B.V. 100.0 The Netherlands