?- Advanced Emissions Solutions Inc.
- Albemarle Corporation
- Cabot Corporation
- Carbon Activated Corporation
- CARBOTECH
- CPL Activated Carbons
- Donau Carbon GmbH
- Evoqua Water Technologies LLC
- Haycarb (Pvt.) Ltd
- Ingevity
- Jacobi Carbons Group
- Kuraray Co. Ltd
- Kureha Corporation
- Puragen Activated Carbons
- Silcarbon Aktivkohle GmbH
- Veolia (Veolia Water Technologies)