| Name | Company Number | Date Appointed | Rating |
|---|---|---|---|
| Malary Environmental Services Ltd | 03445467 | 31/07/2006 | Dissolved |
| Safety Micron Systems U.K. Ltd | 01782348 | 21/04/2005 | Dissolved |
| Name | Company Number | Date Appointed | Date Resigned | Rating |
|---|---|---|---|---|
| SAFETY-KLEEN EUROPE LIMITED | 03686221 | 18/01/2001 | 12/06/2014 | One Red Flag |
| SAFETY-KLEEN U.K. LIMITED | 01190039 | 01/01/2002 | 12/06/2014 | Bronze |
| SAFETY-KLEEN UK (EUROPE) LIMITED | 03673963 | 21/04/2005 | 12/06/2014 | Bronze |
| SAFETY-KLEEN UK (FRANCE) LIMITED | 03673966 | 21/04/2005 | 12/06/2014 | Bronze |
| SAFETYKLEEN FINANCE LIMITED | 06590913 | 24/06/2008 | 12/06/2014 | Bronze |
| SAFETYKLEEN GROUP SERVICES LIMITED | 06544285 | 18/06/2008 | 13/07/2017 | One Red Flag |
| UMMYGUMMY LTD | 09176646 | 05/09/2014 | 17/12/2014 | Dissolved |
| WP MIDCO1 LIMITED | 06544559 | 18/06/2008 | 12/06/2014 | One Red Flag |
| WP MIDCO2 LIMITED | 06544394 | 18/06/2008 | 12/06/2014 | Silver |
| WP MIDCO3 LIMITED | 06544475 | 18/06/2008 | 12/06/2014 | Silver |
| WP SAFETY-KLEEN (CAYMAN) LIMITED | FC028602 | 10/10/2008 | 17/09/2014 | Bronze |
| WP SAFETY-KLEEN LIMITED | 06544225 | 18/06/2008 | 17/09/2014 | Bronze |
| WP SK FRANCE LIMITED | 05134646 | 08/07/2004 | 12/06/2014 | One Red Flag |
| WP SK HOLDINGS LIMITED | 05134411 | 08/07/2004 | 12/06/2014 | Silver |
| WP SK LIMITED | 05134639 | 08/07/2004 | 12/06/2014 | Silver |
| WP SK MIDCO LIMITED | 05385905 | 20/06/2005 | 12/06/2014 | Bronze |