| MIMirror Image on Rd 2 Box 12a, Hartly | Hartly | DE | Chemical Manufacturing325222 | — | ◇ UNVERIFIED |
| MOMobil Oil CORP | Newark | DE | Miscellaneous Manufacturing339112 | — | ◇ UNVERIFIED |
| MOMobil Oil CORP Ss# 17-qgg | Newark | DE | Miscellaneous Manufacturing339112 | — | ◇ UNVERIFIED |
| MPModern Press INC | Wilmington | DE | Chemical Manufacturing325320 | — | ◇ UNVERIFIED |
| NCNcr CORP. (millsboro Plant) | Millsboro | DE | Computer and Electronic Product Manufacturing334118 | — | ◇ UNVERIFIED |
| NANewark Armed Forces Reserve Center | Newark | DE | Chemical Manufacturing325211 | — | ◇ UNVERIFIED |
| NHNew Hue the | Dewey Beach | DE | Miscellaneous Manufacturing339112 | — | ◇ UNVERIFIED |
| NJNews Journal CO | New Castle | DE | Printing and Related Support Activities323111 | — | ◇ UNVERIFIED |
| NCNvf Company INC - Yorklyn Facility | Yorklyn | DE | Paper Manufacturing322214 | — | ◇ UNVERIFIED |
| OCOutlaw Customs - 16 Lincoln St, Dover | Dover | DE | Miscellaneous Manufacturing339112 | — | ◇ UNVERIFIED |
| PSParviz Sorouri Md | Newark | DE | Miscellaneous Manufacturing339112 | — | ◇ UNVERIFIED |
| PAPats Aircraft, LLC | Georgetown | DE | Transportation Equipment Manufacturing336413 | — | ◇ UNVERIFIED |
| PCPaul Campanella's Auto and Tire Center | Wilmington | DE | Miscellaneous Manufacturing339112 | — | ◇ UNVERIFIED |
| PBPeppers Body Works | Dover | DE | Chemical Manufacturing325222 | — | ◇ UNVERIFIED |
| PFPerma - Flex Rollers (closed) | Newark | DE | Fabricated Metal Product Manufacturing332991 | — | ◇ UNVERIFIED |
| PPPlaytex Products INC | Dover | DE | Paper Manufacturing322291 | — | ◇ UNVERIFIED |
| PIPpg Inds INC Works 32 | Newark | DE | Nonmetallic Mineral Product Manufacturing327215 | — | ◇ UNVERIFIED |
| PIPpg Industries Architectural Finishes | Dover | DE | Chemical Manufacturing325510 | — | ◇ UNVERIFIED |
| PAPreston Auto Body of Wilmington | Wilmington | DE | Miscellaneous Manufacturing339112 | — | ◇ UNVERIFIED |
| PPProcino Plating | Blades | DE | Fabricated Metal Product Manufacturing332813 | — | ◇ UNVERIFIED |
| PCPtfe Compounds INC | New Castle | DE | Chemical Manufacturing325211 | — | ◇ UNVERIFIED |
| PBPuzs Body Shop INC | Newark | DE | Miscellaneous Manufacturing339112 | — | ◇ UNVERIFIED |
| QLQps, LLC | Newark | DE | Miscellaneous Manufacturing339112 | — | ◇ UNVERIFIED |
| QAQuality Auto Care - 700 Forest St, Dover | Dover | DE | Miscellaneous Manufacturing339112 | — | ◇ UNVERIFIED |
| QAQuality Auto Care Center - Rt 42, Cheswold | Cheswold | DE | Miscellaneous Manufacturing339112 | — | ◇ UNVERIFIED |
| RCRainbow Cleaners | Wilmington | DE | Miscellaneous Manufacturing339112 | — | ◇ UNVERIFIED |
| RLRed Lion Medical Safety INC | Newark | DE | Miscellaneous Manufacturing339112 | — | ◇ UNVERIFIED |
| RTReynolds Towing | Bear | DE | Miscellaneous Manufacturing339112 | — | ◇ UNVERIFIED |
| RARichs Auto Body Rd 1 Box 73a, Dagsboro | Dagsboro | DE | Miscellaneous Manufacturing339112 | — | ◇ UNVERIFIED |
| RMR & M Trucking | Lincoln | DE | Miscellaneous Manufacturing339112 | — | ◇ UNVERIFIED |
| RARohm and Haas Electronic Materials Cmp INC | Newark | DE | Chemical Manufacturing325612 | — | ◇ UNVERIFIED |
| RFRoos Foods - 251 Cooper St, Kenton | Kenton | DE | Miscellaneous Manufacturing339112 | — | ◇ UNVERIFIED |
| SPSchering Plough Animal Health - 369 West Dupont Highway, Millsboro | Millsboro | DE | Chemical Manufacturing325414 | — | ◇ UNVERIFIED |
| SLSeaboard Lumber - Rt 18 West, Bridgeville | Bridgeville | DE | Miscellaneous Manufacturing339112 | — | ◇ UNVERIFIED |
| STSeiberlich Trane Service | Wilmington | DE | Miscellaneous Manufacturing339112 | — | ◇ UNVERIFIED |
| SCSeymours Cleaners | Wilmington | DE | Miscellaneous Manufacturing339112 | — | ◇ UNVERIFIED |
| S1Shell 1416 - Talleyville | Wilmington | DE | Chemical Manufacturing325211 | — | ◇ UNVERIFIED |
| SHShellhorn & Hill a Street Terminal | Wilmington | DE | Miscellaneous Manufacturing339112 | — | ◇ UNVERIFIED |
| SOShell Oil Company | Newark | DE | Miscellaneous Manufacturing339112 | — | ◇ UNVERIFIED |
| SCShooters Choice - 5105 North Dupont Highway, Dover | Dover | DE | Miscellaneous Manufacturing339112 | — | ◇ UNVERIFIED |
| SHSiemens Healthcare Diagnostics - Rt 896, Glasgow | Newark | DE | Chemical Manufacturing325412 | — | ◇ UNVERIFIED |
| SLSolenis, LLC | Wilmington | DE | Chemical Manufacturing325998 | — | ◇ UNVERIFIED |
 Southern States/milford CO Op | Milford | DE | Chemical Manufacturing325222 | — | ◇ UNVERIFIED |
| SGSpeedy Gas | Newark | DE | Miscellaneous Manufacturing339112 | — | ◇ UNVERIFIED |
| SPSpi Polyols INC. | New Castle | DE | Chemical Manufacturing325199 | — | ◇ UNVERIFIED |
| SOSquare One Electric Service - 347 Fork Branch Rd, Dover | Dover | DE | Chemical Manufacturing325222 | — | ◇ UNVERIFIED |
| SCStandard Chlorine of Delaware, INC. Superfund Site | New Castle | DE | Chemical Manufacturing325100 | — | ◇ UNVERIFIED |
| SEStar Enterprise | Newark | DE | Miscellaneous Manufacturing339112 | — | ◇ UNVERIFIED |
| SOState of Delaware Graphics & Printing - 604 Otis Dr, Dover | Dover | DE | Chemical Manufacturing325211 | — | ◇ UNVERIFIED |
| SASumpter Auto Refinishing | Dover | DE | Chemical Manufacturing325222 | — | ◇ UNVERIFIED |
