| OECD | Organisation for Economic Co-operation and Development |
|---|---|
| OEF | oxygen extraction fraction |
| OEL | Occupational Exposure Limit |
| OEM | Occupational and Environmental Medicine |
| Oep | One-eyed pinhead |
| OER | Oxygen Enhancement Ratio |
| OER | oxygen extraction ratio |
| OERP | olfactory event-related potential |