The OEL (occupational exposure limit) is defined as the maximum concentration of a harmful substance in the air at the work place.
The contact with dust can be cause illness if
- The concentration is very high
- The dust particles are small enough to allow them to reach deep into the lungs (alveoli) via the windpipe and trachea
- The shape of the particles (e.g. Fibres) is beneficial for ingestion
- The dust contains poisonous substances
The specific properties of the medium concerned are important for the type of extraction, filtration and transport of dusts. The various types of dust vary based on the grain size, bulk weight, moisture content, temperature and other key figures (for example, abrasiveness, hygroscopicity). These factors have a considerable effect on the design of the extraction system.