Controlling Silica Dust
The Dangers of Dust
Drilling or cutting concrete, stone, brick and similar products produces dust. This dust can causes annoyance for anyone nearby who did not wish to end up dusty and it can present a serious health hazard.
Hazardous dust can be loosely divided into 'inhalable' and 'respirable' dust:
Inhalable dust is the larger particles. These are usually visible to the naked eye and can get into the mouth, nose and parts of the lungs. Respirable dust is the finer particles. These are usually invisibly small and can get right down into the deepest part of the lungs, known as the gas exchange region. The gas exchange region is where oxygen is absorbed into the blood and carbon dioxide is released from the body back into the air.
Concrete, brick, stone and similar materials can contain between 20% and 70% crystalline silica. When released into the air, for instance by cutting or drilling, the fine Respirable Crystalline Silica (RCS) dust can be inhaled and can get deep into the lungs.
RCS dust consists of very tiny but sharp crystalline dust particles. These can damage the gas exchange region of the lungs causing scar tissue to develop. Over-exposure to RCS dust can lead to a number of serious health problems including silicosis, Chronic Obstructive Pulmonary Disease (COPD) which includes bronchitis and emphysema, and lung cancer.
Exposure to high levels of RCS dust can cause acute silicosis which can cause death within a few months.
The filter systems in site vacs are rated L (low) M (medium) or H (high).
Guidance is still in development, but information from the European Power Tools Association suggests that an 'M' rated vac, such at the Makita 447M, will be the minimum acceptable for use with RCS dust. An 'H' rated vac would be even better. Please contact the HSE for up to date guidance.
Vacs with an 'L' rating, or no rating at all, are better than nothing but only just. The filters in these vacs are too coarse to trap the fine RCS dust. The vac will capture the larger inhalable particles but the tiny RCS dust particles will simply pass straight through the vac and be blown back into the air.
VJ Technology is strongly committed to working in partnership with major customers on safety issues that affect our products. We have assisted with several dust-sensitive sites including the 'live' refurbishment of a fully operational maternity unit. Please contact us on 01233 652520 if we may be able to help.