Since some dust particles can be potentially harmful, national authorities have set so-called occupational exposure limits (OEL). These values are upper limits that define the acceptable concentration of hazardous dust in the workplace, based on a time-weighted average throughout an 8-hour workday. OEL values exist for specific dust types and depend on their hazard.
For example, if you work with material containing silica, the dust that is set free while you process the material – e.g. from drilling, chiseling, sawing or grinding – will most likely contain respirable crystalline silica dust (RCS). These particles can be especially dangerous as they can go deep into the lung and reach the lung alveoli, where long-term over-exposure can lead to damage to the respiratory system. In worst cases this might result in the disease called silicosis, which is currently incurable.
Because the health effects of hazardous dust can be dramatic, OEL values are established to protect workers. OEL values vary within the European Union. Some countries have put in place more stringent provisions. You should always check with your local authorities to get the OEL values applying to you.
Do you have any idea what these limits mean in practical terms? The truth is, it is a tiny amount – like a small pinch of salt – and weighing less than a 2 Cent coin.