| SMITH, Graham Richard ACTIVE | Secretary | 19 Mar 2015 | | | | Office 3a Capital Tower, 91 Waterloo Road, London, SE1 8RT, England |
| LIMA SOLLERO, Alberto ACTIVE | Director | 11 Nov 2025 | | England | September 1981 | Office 3a Capital Tower, 91 Waterloo Road, London, SE1 8RT, England |
| ROOSENSCHOON, Emile ACTIVE | Director | 01 Oct 2025 | | England | February 1984 | Office 3a Capital Tower, 91 Waterloo Road, London, SE1 8RT, England |
| SIDDIQI, Saad Naved ACTIVE | Director | 11 Nov 2025 | | England | September 1978 | Office 3a Capital Tower, 91 Waterloo Road, London, SE1 8RT, England |
| MACDONALD, Janet Ann RESIGNED | Secretary | 29 Dec 2005 | 19 Mar 2015 | | | Harsco House Regent Park, 299 Kingston Road, Leatherhead, Surrey, KT22 7SG |
| PORRITT, Kerry Anne Abigail RESIGNED | Secretary | 24 Mar 2005 | 29 Dec 2005 | | | Brushwood House, 22 Clarence Road, Great Malvern, Worcestershire, WR14 3EH |
| SHORT, Stephen Vernon RESIGNED | Secretary | 16 Sep 1992 | 04 Nov 1999 | | | 1 Windsor Road, Radyr, Cardiff, South Glamorgan, CF15 8BP |
| SHORT, Vernon RESIGNED | Secretary | | 02 Oct 1995 | | | 3 Windsor Road, Radyr, Cardiff, South Glamorgan, CF7 6BE |
| WALTERS, Sandra Gail RESIGNED | Secretary | 03 Nov 2004 | 24 Mar 2005 | | | 9 Danvers Way, Caterham, Surrey, CR3 5FJ |
| WARREN, Rafe Anthony RESIGNED | Secretary | 04 Nov 1999 | 03 Nov 2004 | | | 7 Yarrow Close, Rushden, Northamptonshire, NN10 0XL |
| BURNS, Roderick RESIGNED | Director | 10 Dec 2010 | 10 Dec 2010 | England | December 1966 | Harsco House Regent Park, 299 Kingston Road, Leatherhead, Surrey, KT22 7SG |
| CLAESSENS, Anton Johan RESIGNED | Director | 04 Nov 1999 | 29 Dec 2005 | | June 1948 | Oudstrijderslei 11, 2130 Brasschaat, Brussels, Belgium |
| COOPER, Stephen Richard RESIGNED | Director | 12 Jun 2014 | 01 Oct 2025 | England | December 1966 | Office 3a Capital Tower, 91 Waterloo Road, London, SE1 8RT, England |
| DAVIES, Stephen Robert RESIGNED | Director | 04 Nov 1999 | 21 Jan 2005 | Wales | November 1964 | Woodgate, Church View Baglan, Port Talbot, West Glamorgan, SA12 8UN |
| FROST, Jonathan Park RESIGNED | Director | 26 Aug 2003 | 27 Apr 2006 | Wales | February 1959 | Greengables Main Road, Peterston Super Ely, Cardiff, CF5 6LH |
| HOAD, Martin Roger Gregory RESIGNED | Director | 10 Dec 2010 | 01 Nov 2011 | United Kingdom | November 1965 | Harsco House Regent Park, 299 Kingston Road, Leatherhead, Surrey, KT22 7SG |
| HOBBS, Emmet John RESIGNED | Director | 04 Nov 1999 | 04 Nov 2002 | | January 1942 | 34 Cambrian Road, Richmond, Surrey, TW10 6JQ |
| HUNT, James Joseph RESIGNED | Director | 29 Dec 2005 | 10 Dec 2010 | United Kingdom | December 1951 | 3 Croft Close, Whirlow, Sheffield, South Yorkshire, S11 9QP |
| JAMES, Jeffrey Arthur RESIGNED | Director | 04 Nov 1999 | 25 Oct 2007 | | March 1947 | 46 Hazel Mead, Bryncethin, Bridgend, Mid Glamorgan, CF32 9AQ |
| JAMES, Jeffrey Arthur RESIGNED | Director | 03 Feb 1992 | 04 Nov 1999 | | March 1947 | 46 Hazel Mead, Bryncethin, Bridgend, Mid Glamorgan, CF32 9AQ |
| KIRKWOOD, Clyde RESIGNED | Director | 01 Sep 2009 | 10 Dec 2010 | United Kingdom | September 1964 | High Pines, 14 Douglas Grove, Farnham, Surrey, GU10 3HP |
| LAURENT, Jean Louis RESIGNED | Director | 04 Nov 1999 | 29 Dec 2005 | | November 1947 | 32 Avenue Des Pinsons, Waterloo, B1410, Belgium |
| LECLERCQ, Herve Michal RESIGNED | Director | 03 Oct 2011 | 16 Dec 2013 | United Kingdom | June 1962 | Harsco House Regent Park, 299 Kingston Road, Leatherhead, Surrey, KT22 7SG |
| MACDONALD, Alexander James RESIGNED | Director | 10 Dec 2010 | 10 Dec 2010 | United Kingdom | December 1954 | Harsco House Regent Park, 299 Kingston Road, Leatherhead, Surrey, KT22 7SG |
| O'KELLY, Paul Brian RESIGNED | Director | 10 Dec 2010 | 10 Dec 2010 | United Kingdom | December 1957 | Harsco House Regent Park, 299 Kingston Road, Leatherhead, Surrey, KT22 7SG |
| REITEMEIER, Christophe Nicolas RESIGNED | Director | 06 Nov 2020 | 02 Dec 2025 | England | December 1965 | Office 3a Capital Tower, 91 Waterloo Road, London, SE1 8RT, England |
| RILEY, Paul RESIGNED | Director | 04 Nov 1999 | 01 Apr 2005 | | October 1959 | 15 Cricket Lane, Normanby, Middlesbrough, Cleveland, TS6 0HJ |
| SHORT, Ieuan Gale RESIGNED | Director | 04 Nov 1999 | 31 Dec 2000 | | July 1953 | 9 Pant Glas Court, Bassaleg, Newport, Gwent, NP1 9JE |
| SHORT, Ieuan Gale RESIGNED | Director | | 04 Nov 1999 | | July 1953 | 9 Pant Glas Court, Bassaleg, Newport, Gwent, NP1 9JE |
| SHORT, James Gabriel RESIGNED | Director | | 04 Nov 1999 | Wales | August 1919 | 1 Windsor Road, Radyr, Cardiff, South Glamorgan, CF4 8BP |
| SHORT, Nigel Vernon RESIGNED | Director | 04 Nov 1999 | 03 Jan 2003 | Guernsey | September 1962 | Hazelwell House, Whitland, Dyfed, SA34 0LU |
| SHORT, Nigel Vernon RESIGNED | Director | | 04 Nov 1999 | | September 1962 | Flat 38 Victoria Quay, Maritime Quarter, Swansea, West Glamorgan, SA1 3XG |
| SHORT, Stephen Vernon RESIGNED | Director | 03 Feb 1992 | 04 Nov 1999 | Wales | October 1972 | 1 Windsor Road, Radyr, Cardiff, South Glamorgan, CF15 8BP |
| SHORT, Vernon RESIGNED | Director | | 02 Oct 1995 | | February 1917 | 3 Windsor Road, Radyr, Cardiff, South Glamorgan, CF7 6BE |
| STUBBS, Graham Martin RESIGNED | Director | 10 Dec 2010 | 01 Jul 2014 | United Kingdom | February 1954 | Harsco House Regent Park, 299 Kingston Road, Leatherhead, Surrey, KT22 7SG |
| SWEENEY, John Joseph RESIGNED | Director | 03 Oct 2011 | 01 Jul 2014 | Luxembourg | October 1952 | Harsco House Regent Park, 299 Kingston Road, Leatherhead, Surrey, KT22 7SG |
| THOMAS, Colin Stuart RESIGNED | Director | 03 Feb 1993 | 30 Jun 1997 | | June 1930 | 4 Newman Close, Newport, Gwent, NP9 9NB |
| TREKELS, Luc Henri RESIGNED | Director | 04 Nov 1999 | 05 Nov 2002 | | March 1948 | Avenue Des Cyclistes 34, B-1150 Woluwe-Saint-Pierre, Belgium |
| UNDERWOOD, Eric RESIGNED | Director | 29 Dec 2005 | 24 Aug 2009 | | April 1945 | 11 Beech Avenue, Rotherham, South Yorkshire, S65 3HN |
| WHISTLER, Christopher Claude Lashmer RESIGNED | Director | 10 Dec 2010 | 31 Dec 2020 | England | June 1958 | Harsco House Regent Park, 299 Kingston Road, Leatherhead, Surrey, KT22 7SG |
| ZAMAN, Shaima RESIGNED | Director | 05 Dec 2024 | 11 Nov 2025 | England | December 1976 | Office 3a Capital Tower, 91 Waterloo Road, London, SE1 8RT, England |