EXHIBIT 10.5.1 SAFETY-KLEEN CORP. SEVERANCE AGREEMENT PARTICIPANTS John G. Johnson, Jr. President and Chief Operating Officer Hyman K. Bielsky Senior Vice President/General Counsel James L. Breece Vice President, Technical Roy D. Bullinger Divisional Vice President Robert J. Burian Senior Vice President, Administration Michael H. Carney Senior Vice President, Marketing Glenn R. Casbourne Vice President, Engineering Joseph Chalhoub Senior Vice President, Processing, Engineering & Oil Recovery David A. Dattilo Senior Vice President, Sales and Service Scott E. Fore Senior Vice President, Environment, Health & Safety F. Henry Habicht, II Senior Vice President, Strategic/ Environmental Planning James M. Isanhart Divisional Vice President William P. Kasko Senior Vice President, Operations and Information Wallace K. Louder Vice President, Information Systems Ulisse Marini Vice President, Recycle Center Operations Clyde R. Phillips Divisional Vice President Clark J. Rose Vice President, Technical Services Laurence M. Rudnick Treasurer John Rycombel Controller Robert W. Willmschen, Jr. Senior Vice President, Finance