| HCHenkel Corporation - Adhesive Technologies | Riviera Beach | FL | — | ◐ LIKELY ACTIVE |
| HCHenwil CORP Swi | Newell | PA | — | ◐ LIKELY ACTIVE |
| HSHF Sinclair Woods Cross Refining LLC (2) | West Bountiful | UT | 100–499 | ◐ LIKELY ACTIVE |
| HAHilcorp Alaska Greater Prudhoe Bay Gathering Centers and Well Pads | Prudhoe Bay | AK | — | ◐ LIKELY ACTIVE |
| HTHilco Technologies | Caledonia | MI | 20–99 | ◐ LIKELY ACTIVE |
| HTHilco Technologies | Grand Rapids | MI | 20–99 | ◐ LIKELY ACTIVE |
| HIHoneywell International INC - Chesterfield | Chester | VA | — | ◐ LIKELY ACTIVE |
| HCHooker Chem & Plastics | North Tonawanda | NY | — | ◐ LIKELY ACTIVE |
| HCHorsehead CORP - Monaca Smelter | Monaca | PA | — | ◐ LIKELY ACTIVE |
| HHouston | Houston | TX | 100–499 | ◐ LIKELY ACTIVE |
| HCHunt Crude Oil Melvin Station | Melvin | AL | — | ◐ LIKELY ACTIVE |
Huntsman Advanced Materials Americas LLC | Akron | OH | 20–99 | ◐ LIKELY ACTIVE |
| HBHuntsman Building Solutions - Arlington TX | Arlington | TX | 20–99 | ◐ LIKELY ACTIVE |
| HEHuntsman Ethyleneamines | Freeport | TX | — | ◐ LIKELY ACTIVE |
| HMHuntsman - Mcintosh Operations | Mc Intosh | AL | — | ◐ LIKELY ACTIVE |
| HSHunt Southland Lumberton Refinery | Lumberton | MS | — | ◐ LIKELY ACTIVE |
| IAIcl-ip America INC. | Gallipolis Ferry | WV | 100–499 | ◐ LIKELY ACTIVE |
| ISIcl Specialty Products INC Carondelet Plant | Saint Louis | MO | — | ◐ LIKELY ACTIVE |
| IKIes - Kapolei | Kapolei | HI | — | ◐ LIKELY ACTIVE |
| ICImerys Carbonates LLC | Sylacauga | AL | — | ◐ LIKELY ACTIVE |
| IAINCA Acquisitions DBA Dometic Marine Products | Sparta | TN | 100–499 | ◐ LIKELY ACTIVE |
| ITIndependence Technology Center | Independence | OH | — | ◐ LIKELY ACTIVE |
| IVIndorama Ventures Bayport Clear Lake Site | Pasadena | TX | 20–99 | ◐ LIKELY ACTIVE |
Indorama Ventures Oxides LLC | Port Neches | TX | 500+ | ◐ LIKELY ACTIVE |
| IRIndustrial Recyclers, LLC | Sidney | OH | 20–99 | ◐ LIKELY ACTIVE |
| IRIndustrial Resources Network,llc | Wilmington | DE | — | ◐ LIKELY ACTIVE |
| IOIneos Oligomers Chocolate Bayou | Alvin | TX | — | ◐ LIKELY ACTIVE |
| IUIneos US Chemicals Company | Texas City | TX | 20–99 | ◐ LIKELY ACTIVE |
| IWInfiltrator Water Technologies LLC | Winchester | KY | 100–499 | ◐ LIKELY ACTIVE |
| ICInnovative Chemical Technologies, INC. | Augusta | GA | — | ◐ LIKELY ACTIVE |
| ICIntematix Corporation | Fremont | CA | 1–19 | ◐ LIKELY ACTIVE |
| ICIntergulf CORP Lonestar Ecology LLC (lonstr) | Pasadena | TX | — | ◐ LIKELY ACTIVE |
| ISIntergulf - Strang Rd Facility | La Porte | TX | — | ◐ LIKELY ACTIVE |
| ITInternational-matex Tank Terminals (st. Rose) | Saint Rose | LA | — | ◐ LIKELY ACTIVE |
| IOInventek of Mt Laurel | Mount Laurel | NJ | — | ◐ LIKELY ACTIVE |
| MP(IPL) Macro Plastics | Shelbyville | KY | 100–499 | ◐ LIKELY ACTIVE |
| ICIsp Chemicals LLC | Calvert City | KY | — | ◐ LIKELY ACTIVE |
| JFJacksonville Facility | Jacksonville | FL | 20–99 | ◐ LIKELY ACTIVE |
Johns Manville Technical Center | Littleton | CO | — | ◐ LIKELY ACTIVE |
| JCJwa Co., LTD. | Kokomo | IN | — | ◐ LIKELY ACTIVE |
| KPK2 Pure Solutions | Pittsburg | CA | 20–99 | ◐ LIKELY ACTIVE |
| KPK2 Pure Solutions - Pittsburg Plant | Pittsburg | CA | — | ◐ LIKELY ACTIVE |
| KRKairos Research | Wilmington | NC | — | ◐ LIKELY ACTIVE |
| KWKemira Water Solutions, INC. | Fontana | CA | — | ◐ LIKELY ACTIVE |
| KOKern Oil & Refinery CO. | Bakersfield | CA | — | ◐ LIKELY ACTIVE |
| KIKicksplosion, INC. | Newnan | GA | 1–19 | ◐ LIKELY ACTIVE |
| KMKinder Morgan Wilmington Terminal | Wilmington | NC | — | ◐ LIKELY ACTIVE |
| KCKing Cnty Solid Wst Cedar Hills Landfill | Maple Valley | WA | — | ◐ LIKELY ACTIVE |
| KIKing Industries | Waterbury | CT | — | ◐ LIKELY ACTIVE |
| KFKnf Flexpak Corporation | Tamaqua | PA | 20–99 | ◐ LIKELY ACTIVE |