| Abbreviation | Definition |
|---|---|
| OBC | Organic and Biomolecular Chemistry |
| OBC | Organic Biomolecular Chemistry |
| OC | Optimal Classification |
| OC | Organic Carbon |
| OCAW | Oil Chemical and Atomic Workers |
| OCAW | Oil, Chemical and Atomic Workers |
| OCB | Ocean Carbon and Biogeochemistry |
| OCCA | Oil Colour Chemists Association |
| OCID | Online Chemical Inventory Database |
| OCLV | Optimum Compaction Low Void |
| OCNS | Offshore Chemical Notification Scheme |
| OCPP | Online Chemistry Placement and Preparation |
| OCPP | Online Chemistry Placement Preparation |
| OCPT | Organic Chemistry Peer Tutoring |
| OCPW | Organisation for the Prohibition of Chemical Weapons |
| OCSG | Offshore Chemical Selection Guidelines |
| OCTC | Ohio Chemistry Technology Council |
| OCTM | Ocean Chemical Transport Model |
| ODAB | Octyl-p-(Dimethyl-Amino)- Benzoate |
| ODC | Orthogonal Defect Classification |