Olf (unit)
# Olf (unit)

The olf is a unit used to measure the strength of a pollution source. It was introduced by Danish professor P. Ole Fanger; the name "olf" is derived from the Latin word olfactus, meaning "smelled".

One olf is the sensory pollution strength from a standard person defined as an average adult working in an office or similar non-industrial workplace, sedentary and in thermal comfort, with a hygienic standard equivalent of 0.7 baths per day and whose skin has a total area of 1.8 square metres. It was defined to quantify the strength of pollution sources that can be perceived by humans.

The perceived air quality is measured in decipol.

## Examples of typical scent emissions

| Person/object | Scent emission |
| - | - |
| Sitting person | 1 olf |
| Smoker | 25 olf |
| Athlete | 30 olf |
| Marble | 0.01 olf/m² |
| Linoleum | 0.2 olf/m² |
| Synthetic fibre | 0.4 olf/m² |
| Rubber gasket | 0.6 olf/m² |
