What is Silicosis?
There are serious health risks caused by exposure to Respirable Crystalline Silica (RCS) for workers in the stone benchtop manufacturing, finishing and installation industries. Health monitoring of workers in the stone benchtop industry in Australia has found numerous cases of workers suffering silicosis. When silica dust enters the lungs it scratches the surface of tissue in the respiratory system, leading to scarring that blocks the absorption of oxygen. Exposure to silica dust can lead to the development of lung cancer, silicosis (an irreversible scarring and stiffening of the lungs), kidney disease and chronic obstructive pulmonary disease. It is estimated that 230 people develop lung cancer each year as a result of past exposure to silica dust at work. Not all exposed workers will develop cancer; cancer risk increases with long term or repeated high level exposure. (Cancer Council Australia)
What is Crystalline Silica?
Crystalline silica is essentially quartz. Crystalline solids have regular ordered arrays of components held together by uniform intermolecular forces, as opposed to the components of amorphous solids (glass) which are not arranged in regular arrays. A good example of Crystalline Silica is quartz beach sand. Now of course beach sand isn’t going to cause the type of disease as outlined above. It is the Respirable fraction of silica dust that is the danger. That is, particles < 10 microns which easily settle into the Alveolar region of the lungs.
Is there Respirable Crystalline Silica in cement?
In short, the RCS fraction in cement is below the limit of detection. When quartz is introduced into the cement kiln, the high temperatures eventually disseminate the crystal structure of any quartz present and the subsequent free silica then reacts with other elements to form new minerals. At the intermediate point in the kiln (at about 1000℃) the semi molten mixture becomes amorphous. Now there will be Crystalline Silica in “concrete” and “mortar” because sand (silica quartz) is a primary component of these materials. The primary risk of exposure to RCS is when these materials are cut or ground resulting in airborne dust.
No dust is good dust
Always ensure that the recommended personal protective equipment is used when working with cement. Use a dust mask to prevent inhalation of airborne dust. Even though the level of RCS is negligible, both acute and chronic respiratory problems are preventable by using the correct personal protective equipment. See the relevant Safety data Sheet on the Cement Australia website for more information.