Exhibit 21.1

Active Subsidiaries of Nalco Holding Company



|                                                 |  |                           
|------------------------------------------------ |  | --------------------------
|Derypol SA                                       |  | Spain                     
|Katayama Nalco Inc.                              |  | Japan                     
|Malaysian Energy Chem & Services Sdn Bhd         |  | Malaysia                  
|Nalco (Shanghai) Trading Co. Ltd.                |  | Peoples Republic of China
|Nalco Anadolu Kimya Sanayii Ve Ticaret AS        |  | Turkey                    
|Nalco Argentina S.R.L.                           |  | Argentina                 
|Nalco Australia Pty. Ltd.                        |  | Australia                 
|Nalco Belgium NV/SA                              |  | Belgium                   
|Nalco Brasil Ltda                                |  | Brazil                    
|Nalco Canada Co.                                 |  | Canada                    
|Nalco Company                                    |  | Delaware                  
|Nalco Company OOO                                |  | Russia                    
|Nalco de Colombia Ltda                           |  | Colombia                  
|Nalco de Mexico, S. de R.L. de C.V.              |  | Mexico                    
|Nalco Deutschland GmbH                           |  | Germany                   
|Nalco Egypt, Ltd.                                |  | Egypt                     
|Nalco Egypt Trading                              |  | Egypt                     
|Nalco Energy Services Equatorial Guinea LLC      |  | Delaware                  
|Nalco Espanola, S.A.                             |  | Spain                     
|Nalco Europe B.V.                                |  | Netherlands               
|Nalco Finance Holdings LLC                       |  | Delaware                  
|Nalco Finland OY                                 |  | Finland                   
|Nalco France                                     |  | France                    
|Nalco Gulf Limited                               |  | Jersey                    
|Nalco Hellas S.A.                                |  | Greece                    
|Nalco Hong Kong Limited                          |  | Hong Kong                 
|Nalco Hungary KFT                                |  | Hungary                   
|Nalco Industrial Services Chile Limitada         |  | Chile                     
|Nalco Industrial Services Malaysia SDN BHD       |  | Malaysia                  
|Nalco Industrial Services (Nanjing) Co.          |  | Peoples Republic of China
|Nalco Industrial Services (Su Zhou) Co.          |  | Peoples Republic of China
|Nalco Industrial Services (Thailand) Co. Limited |  | Thailand                  
|Nalco Italiana SrL                               |  | Italy                     
|Nalco Korea, Ltd.                                |  | Korea                     
|Nalco Limited                                    |  | United Kingdom            
|Nalco Mobotec, Inc.                              |  | Delaware                  
|Nalco Netherlands B.V.                           |  | Netherlands               
|Nalco New Zealand Limited                        |  | New Zealand               
|Nalco Norge A/S                                  |  | Norway                    
|Nalco Oesterreich Ges m.b.H                      |  | Austria                   
|Nalco Pacific Private, Ltd.                      |  | Singapore                 
|Nalco Receivables LLC                            |  | Delaware                  
|Nalco Saudi Co. Ltd                              |  | Saudi Arabia              
|Nalco (Shanghai) Trading Co. Ltd.                |  | Peoples Republic of China
|Nalco Taiwan Co., Ltd.                           |  | Taiwan                    
|Nalco Venezuela SCA                              |  | Venezuela                 
|NLC Nalco India Limited                          |  | India                     
|PT Nalco Indonesia                               |  | Indonesia                 

The names of the Companys other
subsidiaries are omitted because, considered in the aggregate as a single subsidiary, such subsidiaries would not constitute a significant subsidiary as of December 31, 2009.