**EXHIBIT21**

ü **W. R. GRACE & CO., a Delaware corporationU.S. SUBSIDIARIES**

12/31/2006

ü Chapter 11 Filing — April 2, 2001
|        | ** ** | **SUBSIDIARY  NAME**                     | ** ** | **CO. #**        | ** ** | **STATE OF INCORPORATION** |
|--------|------------|------------------------------------------|------------|------------------|------------|----------------------------|
| ü |       | A-1 Bit & Tool Co., Inc.             |       | 458              |       | DE                         |
|   |       | *Advanced Refining Technologies LLC      |       | 268  (f/k/a 930) |       | DE                         |
| ü |       | Alewife Boston Ltd.                      |       | 070              |       | MA                         |
| ü |       | Alewife Land Corporation                 |       | 069              |       | MA                         |
|   |       | Alltech Associates, Inc.                 |       | 259              |       | IL                         |
| ü |       | Amicon, Inc.                             |       | 174              |       | DE                         |
|   |       | AP Chem Incorporated                     |       | 436              |       | MD                         |
| ü |       | CB Biomedical, Inc.                      |       | 125              |       | DE                         |
| ü |       | CCHP, Inc.                               |       | 074              |       | DE                         |
| ü |       | Coalgrace, Inc.                          |       | 824              |       | DE                         |
| ü |       | Coalgrace II, Inc.                       |       | 835              |       | DE                         |
|   |       | Construction Products Dubai, Inc.        |       | 121              |       | DE                         |
| ü |       | Creative Food ’N Fun Company        |       | 587              |       | DE                         |
| ü |       | Darex Puerto Rico, Inc.                  |       | 798              |       | DE                         |
| ü |       | Del Taco Restaurants, Inc.               |       | 557              |       | DE                         |
| ü |       | Dewey and Almy, LLC                      |       | 406              |       | DE                         |
| ü |       | Ecarg, Inc.                              |       | 519              |       | NJ                         |
| ü |       | Five Alewife Boston Ltd.                 |       | 071              |       | MA                         |
| ü |       | G C Limited Partners I, Inc.             |       | 465              |       | DE                         |
| ü |       | G C Management, Inc.                     |       | 539              |       | DE                         |
| ü |       | GEC Management Corporation               |       | 689              |       | DE                         |
| ü |       | GN Holdings, Inc.                        |       | 073              |       | DE                         |
| ü |       | GPC Thomasville Corp.                    |       | 637              |       | DE                         |
| ü |       | Gloucester New Communities Company, Inc. |       | 572              |       | NJ                         |
| ü |       | Grace A-B Inc.                           |       | 625              |       | DE                         |
| ü |       | Grace A-B II Inc.                        |       | 827              |       | DE                         |
|   |       | Grace Asia Pacific, Inc.                 |       | 107              |       | DE                         |
|   |       | Grace Chemicals, Inc.                    |       | 710              |       | DE                         |
| ü |       | Grace Chemical Company of Cuba           |       | 305              |       | IL                         |
|   |       | Grace Collections, Inc.                  |       | 316              |       | DE                         |
| ü |       | Grace Culinary Systems, Inc.             |       | 479              |       | MD                         |
| ü |       | Grace Drilling Company                   |       | 877              |       | DE                         |

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*                    Ownership of Advanced Refining Technologies LLC is 55%W. R. Grace & Co.-Conn. (#001) and 45%Chevron USA, Inc.; certain enumeratedactions of the Executive Committee require unanimous consent.

 

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|        | ** ** | **SUBSIDIARY  NAME**                        | ** ** | **CO. #** | ** ** | **STATE OF INCORPORATION** |
|--------|------------|---------------------------------------------|------------|-----------|------------|----------------------------|
| ü |       | Grace Energy Corporation                    |       | 681       |       | DE                         |
| ü |       | Grace Environmental, Inc.                   |       | 198       |       | DE                         |
| ü |       | Grace Europe, Inc.                          |       | 407       |       | DE                         |
|   |       | Grace Germany Holdings, Inc.                |       |      |       | DE                         |
| ü |       | Grace H-G Inc.                              |       | 506       |       | DE                         |
| ü |       | Grace H-G II Inc.                           |       | 828       |       | DE                         |
| ü |       | Grace Hotel Services Corporation            |       | 480       |       | DE                         |
| ü |       | Grace International Holdings, Inc.          |       | 543       |       | DE                         |
|   |       | Grace Latin America, Inc.                   |       | 263       |       | DE                         |
|   |       | Grace Management Services, Inc.             |       | 485       |       | DE                         |
| ü |       | Grace Offshore Company                      |       | 822       |       | LA                         |
| ü |       | Grace PAR Corporation                       |       | 621       |       | DE                         |
| ü |       | Grace Petroleum Libya Incorporated          |       | 880       |       | DE                         |
|   |       | Grace Receivables Purchasing, Inc.          |       | 041       |       | DE                         |
| ü |       | Grace Tarpon Investors, Inc.                |       | 462       |       | DE                         |
| ü |       | Grace Ventures Corp.                        |       | 664       |       | DE                         |
| ü |       | Grace Washington, Inc.                      |       | 197       |       | DE                         |
| ü |       | W. R. Grace Capital Corporation             |       | 563       |       | NY                         |
| ü |       | W. R. Grace & Co.-Conn.                 |       | 001       |       | CT                         |
| ü |       | W. R. Grace Land Corporation                |       | 523       |       | NY                         |
| ü |       | Gracoal, Inc.                               |       | 856       |       | DE                         |
| ü |       | Gracoal II, Inc.                            |       | 848       |       | DE                         |
| ü |       | Guanica-Caribe Land Development Corporation |       | 376       |       | DE                         |
| ü |       | Hanover Square Corporation                  |       | 516       |       | DE                         |
| ü |       | Homco International, Inc.                   |       | 631       |       | DE                         |
|   |       | Ichiban Chemical Co., Inc.                  |       | 028       |       | DE                         |
| ü |       | Kootenai Development Company                |       | 079       |       | MT                         |
| ü |       | L B Realty, Inc.                            |       | 495       |       | DE                         |
| ü |       | Litigation Management, Inc.                 |       | 317       |       | DE                         |
| ü |       | Monolith Enterprises, Incorporated          |       | 477       |       | DC                         |
| ü |       | Monroe Street, Inc.                         |       | 481       |       | DE                         |
| ü |       | MRA Holdings Corp.                          |       | 075       |       | DE                         |
| ü |       | MRA Intermedco, Inc.                        |       | 076       |       | DE                         |
| ü |       | MRA Staffing Systems, Inc.                  |       | 077       |       | DE                         |
|   |       | NZ Alltech, Inc.                            |       |      |       | IL                         |
| ü |       | Remedium Group, Inc.                        |       | 063       |       | DE                         |
| ü |       | Southern Oil, Resin & Fiberglass, Inc.  |       | 318       |       | FL                         |
| ü |       | Water Street Corporation                    |       | 548       |       | DE                         |

 

2

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**NON-U.S.SUBSIDIARIES**
| COUNTRY/SUBSIDIARY NAME                   | ** ** | ** ** |
|-------------------------------------------|------------|------------|
| **ARGENTINA**                             |       |       |
| W. R. Grace  Argentina S.A.               |       |       |
| WRG Argentina,  S.A.                      |       |       |
| **AUSTRALIA**                             | ** ** | ** ** |
| Alltech  Associates (Australia) Pty. Ltd. |       |       |
| Grace Australia  Pty. Ltd.                |       |       |
| **BELGIUM**                               | ** ** | ** ** |
| Grace  Construction Products N.V.         |       |       |
| Grace N.V.                                |       |       |
| Grace Silica  N.V.                        |       |       |
| Inverco Benelux  N.V.                     |       |       |
| **BRAZIL**                                | ** ** | ** ** |
| Grace Brasil  Ltda.                       |       |       |
| Grace Davison  Ltda.                      |       |       |
| **CANADA**                                | ** ** | ** ** |
| GEC Divestment  Corporation Ltd.          |       |       |
| Grace Canada,  Inc.                       |       |       |
| W. R. Grace  Finance (NRO) Ltd.           |       |       |
| **CHILE**                                 | ** ** | ** ** |
| Grace Quimica  Compania Limitada          |       |       |
| **CHINA -  PEOPLE’S REPUBLIC OF**    | ** ** | ** ** |
| Grace China Ltd.                          |       |       |
| Grace Trading  (Shanghai) Co., Ltd.       |       |       |
| **COLOMBIA**                              | ** ** | ** ** |
| Grace Colombia  S.A.                      |       |       |
| W. R. G.  Colombia S.A.                   |       |       |
| **CUBA**                                  | ** ** | ** ** |
| Envases  Industriales y Comerciales, S.A. |       |       |
| Papelera  Camagueyana, S.A.               |       |       |
| **FRANCE**                                | ** ** | ** ** |
| Alltech France  S.A.R.L.                  |       |       |
| Grace Produits  de Construction SAS       |       |       |
| Société Civile  Beau-Béton |       |       |
| W. R. Grace S.A.                          |       |       |
| **GERMANY**                               | ** ** | ** ** |
| Advanced  Refining Technologies GmbH      |       |       |
| Alltech Grom  GmbH                        |       |       |
| Grace  Bauprodukte GmbH                   |       |       |
| Grace Darex GmbH                          |       |       |
| Grace GP  G.m.b.H.                        |       |       |
| Grace Holding  G.m.b.H.                   |       |       |
| Grace Management  GP G.m.b.H.             |       |       |
| Grace Silica  GmbH                        |       |       |

3

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| COUNTRY/SUBSIDIARY NAME                               | ** ** | ** ** |
|-------------------------------------------------------|------------|------------|
| **GREECE**                                            | ** ** | ** ** |
| Grace Hellas  E.P.E.                                  |       |       |
| **HONG  KONG**                                        | ** ** | ** ** |
| Alltech Applied  Science Labs (HK) Limited            |       |       |
| Alltech  Scientific (China) Limited                   |       |       |
| W. R. Grace  (Hong Kong) Limited                      |       |       |
| W. R. Grace  Southeast Asia Holdings Limited          |       |       |
| **HUNGARY**                                           | ** ** | ** ** |
| Grace Értékesito  Kft.                      |       |       |
| **INDIA**                                             | ** ** | ** ** |
| Flexit  Laboratories Private Ltd.                     |       |       |
| W. R. Grace  & Co. (India) Private Limited        |       |       |
| **INDONESIA**                                         | ** ** | ** ** |
| PT. Grace  Specialty Chemicals Indonesia              |       |       |
| **IRELAND**                                           | ** ** | ** ** |
| Amicon Ireland  Limited                               |       |       |
| Grace  Construction Products (Ireland) Limited        |       |       |
| Trans-Meridian  Insurance (Dublin) Ltd.               |       |       |
| **ITALY**                                             | ** ** | ** ** |
| Alltech Italia  S.R.L.                                |       |       |
| W. R. Grace  Italiana S.p.A.                          |       |       |
| **JAPAN**                                             | ** ** | ** ** |
| Advanced  Refining Technologies K.K.                  |       |       |
| Grace Chemicals  K.K.                                 |       |       |
| Grace Japan  Kabushiki Kaisha                         |       |       |
| **KOREA**                                             | ** ** | ** ** |
| Grace Korea Inc.                                      |       |       |
| **MALAYSIA**                                          | ** ** | ** ** |
| W. R. Grace  (Malaysia) Sendiran Berhad               |       |       |
| W. R. Grace  Specialty Chemicals (Malaysia) Sdn. Bhd. |       |       |
| **MEXICO**                                            | ** ** | ** ** |
| Grace Container,  S. A. de C. V.                      |       |       |
| W. R. Grace  Holdings, S. A. de C. V.                 |       |       |
| **NETHERLANDS**                                       | ** ** | ** ** |
| Alltech Applied  Science B.V.                         |       |       |
| Amicon B.V.                                           |       |       |
| Denac Nederland  B.V.                                 |       |       |
| LC Service B.V.                                       |       |       |
| Storm van Bentem  en Kluyver B.V.                     |       |       |
| W. R. Grace B.V.                                      |       |       |
| **NETHERLANDS  ANTILLES**                             | ** ** | ** ** |
| W. R. Grace N.V.                                      |       |       |
| **NEW  ZEALAND**                                      | ** ** | ** ** |
| Grace (New  Zealand) Limited                          |       |       |
| **PHILIPPINES**                                       |       |       |
| W. R. Grace  (Philippines), Inc.                      |       |       |
| **POLAND**                                            | ** ** | ** ** |
| Grace Sp. z o.o.                                      |       |       |

4

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| COUNTRY/SUBSIDIARY NAME                          | ** ** | ** ** |
|--------------------------------------------------|------------|------------|
| **RUSSIA**                                       | ** ** | ** ** |
| Darex CIS LLC                                    |       |       |
| **SINGAPORE**                                    | ** ** | ** ** |
| W. R. Grace  (Singapore) Private Limited         |       |       |
| **SOUTH  AFRICA**                                | ** ** | ** ** |
| Grace Davison  (Proprietary) Limited             |       |       |
| W. R. Grace  Africa (Proprietary) Limited        |       |       |
| **SPAIN**                                        | ** ** | ** ** |
| Grace, S.A.                                      |       |       |
| Pieri  Especialidades, S.L.                      |       |       |
| **SWEDEN**                                       | ** ** | ** ** |
| Grace AB                                         |       |       |
| Grace Catalyst  AB                               |       |       |
| Grace Sweden AB                                  |       |       |
| **SWITZERLAND**                                  | ** ** | ** ** |
| Pieri S.A.                                       |       |       |
| **TAIWAN**                                       | ** ** | ** ** |
| W. R. Grace  Taiwan, Inc.                        |       |       |
| **THAILAND**                                     | ** ** | ** ** |
| W. R. Grace  (Thailand) Limited                  |       |       |
| **UNITED  KINGDOM**                              | ** ** | ** ** |
| A.A. Consultancy  & Cleaning Company Limited |       |       |
| Alltech  Associates Applied Science Limited      |       |       |
| Cormix Limited                                   |       |       |
| Borndear 1  Limited                              |       |       |
| Borndear 2  Limited                              |       |       |
| Borndear 3  Limited                              |       |       |
| Darex UK Limited                                 |       |       |
| Emerson &  Cuming (Trading) Ltd.             |       |       |
| Emerson &  Cuming (UK) Ltd.                  |       |       |
| Exemere Limited                                  |       |       |
| Grace  Construction Products Limited             |       |       |
| Pieri U.K.  Limited                              |       |       |
| Servicised Ltd.                                  |       |       |
| W. R. Grace  Limited                             |       |       |
| **VENEZUELA**                                    | ** ** | ** ** |
| Grace Venezuela,  S.A.                           |       |       |
| Inversiones GSC,  S.A.                           |       |       |

 

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