Exhibit21.1

Active Subsidiaries of Nalco HoldingCompany

|                                          |  |                            |  |  |  |  |
|------------------------------------------|--|----------------------------|--|--|--|--|
| CalgonCorporation                        |  | Delaware                   |
| Derypol SA                               |  | Spain                      |
| Katayama NalcoInc.                       |  | Japan                      |
| Nalco (Shanghai) Trading Co.Ltd.         |  | People's Republic of China |
| NalcoAcquisition One                     |  | United Kingdom             |
| NalcoAnadolu Kimya Sanayii Ve Ticaret AS |  | Turkey                     |
| Nalco Argentina S.R.L.                   |  | Argentina                  |
| Nalco Australia Pty. Ltd.                |  | Australia                  |
| Nalco Brasil Ltda                        |  | Brazil                     |
| NalcoCanada Co.                          |  | Canada                     |
| NalcoCompany                             |  | Delaware                   |
| Nalco de ColombiaLtda                    |  | Colombia                   |
| Nalco de Mexico, S. de R.L.de C.V.       |  | Mexico                     |
| Nalco DeutschlandGmbH                    |  | Germany                    |
| Nalco Energy ServicesLimited             |  | United Kingdom             |
| Nalco EnergyServices, L.P.               |  | Delaware                   |
| Nalco Espanola,S.A.                      |  | Spain                      |
| Nalco EuropeB.V.                         |  | Netherlands                |
| Nalco Finance HoldingsLLC                |  | Delaware                   |
| Nalco FinlandOY                          |  | Finland                    |
| NalcoFrance                              |  | France                     |
| Nalco Global HoldingsB.V.                |  | Netherlands                |
| Nalco HoldingB.V.                        |  | Netherlands                |
| Nalco Holdings GermanyGmbH               |  | Germany                    |
| Nalco Holdings UKLimited                 |  | United Kingdom             |
| Nalco Hong KongLimited                   |  | Hong Kong                  |
| Nalco IndustrialOutsourcing Company      |  | Delaware                   |
| NalcoIndustrial Services (Su Zhou) Co.   |  | People's Republic ofChina  |
| Nalco Investments U.K. Limited           |  | UnitedKingdom              |
| Nalco Italia SrL                         |  | Italy                      |
| Nalco Japan Co., Ltd                     |  | Japan                      |
| NalcoKorea, Ltd.                         |  | Korea                      |
| NalcoLimited                             |  | United Kingdom             |
| Nalco NetherlandsB.V.                    |  | Netherlands                |
| Nalco New ZealandLimited                 |  | New Zealand                |
| Nalco Oesterreich Gesm.b.H.              |  | Austria                    |
| Nalco Pacific Private,Ltd.               |  | Singapore                  |
| Nalco ReceivablesLLC                     |  | Delaware                   |
| Nalco Taiwan Co.,Ltd.                    |  | Taiwan                     |
| Nalco UK GroupLimited                    |  | United Kingdom             |
| Nalco UniversalHoldings B.V.             |  | Netherlands                |
| Nalco VenezuelaSCA                       |  | Venezuela                  |
| NDCLLC                                   |  | Delaware                   |
| NI Acquisition HoldingsLLC               |  | Delaware                   |
| OekophilAG                               |  | Switzerland                |
| Ondeo Nalco Saudi Co.Ltd.                |  | Saudi Arabia               |
| Paper Chemicals,Inc.                     |  | Texas                      |
| PT NalcoIndonesia                        |  | Indonesia                  |
| Pure-Chem ProductsCompany, Inc.          |  | California                 |
| Treated WaterOutsourcing                 |  | Delaware                   |
|                                          |

The names of theCompany's other subsidiaries are omitted because, considered inthe aggregate as a single subsidiary, such subsidiaries would notconstitute a significant subsidiary as of December 31,2004.

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