| OILD | occupational immunologic lung disease |
|---|---|
| OMAS | occupational maladjustment syndrome |
| OS | left eye [Lat. oculus sinister]; occipitosacral; occupational safety; office surgery; Omenn syndrome... |
| OSHA | Occupational Safety and Health Adminstration |
| OSH | Act Occupational Safety and Health Act of 1970 |