| SHScotts Hyponex | Morrison | — | ◇ UNVERIFIED |
| SMScrap Metal Services LLC | Blue Island | — | ◇ UNVERIFIED |
| SWSherwin Williams CO | Chicago | — | ◇ UNVERIFIED |
| SESiegwerk Eic LLC | West Chicago | — | ◇ UNVERIFIED |
| SASigan America LLC | Ottawa | — | ◇ UNVERIFIED |
| SSSimpson Strong-tie Anchor Systems | Addison | — | ◇ UNVERIFIED |
| SISkokie Istp LLC | Skokie | — | ◇ UNVERIFIED |
| SLSolo Laboratories INC | Blue Island | — | ◇ UNVERIFIED |
| SGSolomon Grind-chem Service INC | Springfield | — | ◇ UNVERIFIED |
| SISolutia INC Krummrich Il (part) | Sauget | — | ◇ UNVERIFIED |
| SUSolvay USA INC | Blue Island | — | ◇ UNVERIFIED |
| SCSpaulding Composites CO | Dekalb | — | ◇ UNVERIFIED |
 Specialty Construction Brands | Aurora | — | ◇ UNVERIFIED |
| SCSpraylat CORP Il | Chicago | — | ◇ UNVERIFIED |
| STStar Thermoplastic | Chicago | — | ◇ UNVERIFIED |
| STStar Thermoplastic Alloys & Rubbers INC | Broadview | — | ◇ UNVERIFIED |
| SCStutz CO | Chicago | — | ◇ UNVERIFIED |
| SCSuncast CORP | Batavia | — | ◇ UNVERIFIED |
 Sun Chemical | Chicago | — | ◇ UNVERIFIED |
| Sun Chemical - General Printing Ink Div | Bedford Park | — | ◇ UNVERIFIED |
| SFSunrise Fs INC | Urbana | — | ◇ UNVERIFIED |
| SPSunstar Pharmaceutical INC | Elgin | — | ◇ UNVERIFIED |
| SMSuperior Manufacturing Group INC | Chicago | — | ◇ UNVERIFIED |
| SHSwisher Hygiene, INC. | Chicago | — | ◇ UNVERIFIED |
| SPSwitzer Products LLC | Richmond | — | ◇ UNVERIFIED |
| TITakasago International CORP (usa) | University Park | — | ◇ UNVERIFIED |
| TCTapecoat CO INC | Evanston | — | ◇ UNVERIFIED |
| TSTec Specialty Products, LLC | Aurora | — | ◇ UNVERIFIED |
| TCTennant Coatings INC | Chicago | — | ◇ UNVERIFIED |
| TDThe Dow Chemical CO | Joliet | — | ◇ UNVERIFIED |
| TCTioga Coatings CORP | Rockford | — | ◇ UNVERIFIED |
| TUTomoegawa USA INC | Wheeling | — | ◇ UNVERIFIED |
| TIToyo Ink America, LLC | Wood Dale | — | ◇ UNVERIFIED |
| TCTri County Fs, Inc.- Carrollton | Carrollton | — | ◇ UNVERIFIED |
| TSTri State Industriallubricants INC | Skokie | — | ◇ UNVERIFIED |
| TVTrue Value Manufacturing CO | Chicago | — | ◇ UNVERIFIED |
| TETyler Enterprises INC | Elwood | — | ◇ UNVERIFIED |
| UHUnilever Home & Personal Care USA | Rolling Meadows | — | ◇ UNVERIFIED |
| UBUnited Bulk Powders and Chemical Packaging Plant | East Saint Louis | — | ◇ UNVERIFIED |
| UGUnited Gilsonite Laboratories | Jacksonville | — | ◇ UNVERIFIED |
| UFUniversal Form Clamp | Bellwood | — | ◇ UNVERIFIED |
| UBUS Bio Marshall LLC | Marshall | — | ◇ UNVERIFIED |
| UIUS Ink a Division of Sun Chemical CORP | Mccook | — | ◇ UNVERIFIED |
| USUtica Silicates Plt | Utica | — | ◇ UNVERIFIED |
| USUv Specialties LLC | Saint Charles | — | ◇ UNVERIFIED |
| VBValent Biosciences | Libertyville | — | ◇ UNVERIFIED |
 Valent Biosciences CORP | Long Grove | — | ◇ UNVERIFIED |
| VPVee Pak INC | Countryside | — | ◇ UNVERIFIED |
| VCVelsicol Chemical CORP. (marshall Plant) | Marshall | — | ◇ UNVERIFIED |
| VIVersatile Inks | Addison | — | ◇ UNVERIFIED |
