Silica and dust

Over the last few years the interest about assessment of dust exposure risk at the workplace has increased, according to the most recent discoveries about health effect of crystalline silica dust.The Scientific Committee on Occupational Exposure Limits (SCOEL) recognized silicosis as the main effect of the cristalyne silice dust on workers, highlighting the fact that affected people have a greater risk of developing lung cancer.

"There is sufficient evidence of the carcinogenicity of respirable crystalline silica dust. On the basis of available information, including scientific and technical data, a limit value for respirable crystalline silica dust should be established. Respirable crystalline silica dust generated by a work process is not subject to classification in accordance with Regulation (EC) No 1272/2008. It is therefore appropriate to include work involving exposure to respirable crystalline silica dust generated by a work process in Annex I to Directive 2004/37/EC and to establish a limit value for respirable crystalline silica dust (‘respirable fraction’) that should be subject to review, in particular in light of the number of workers exposed".

Over the last decades the lab of the National Institute for Silicosis has analized almost all the dust and respirable crystalline silica Spanish samples of companies under the Spanish Mining Safety Regulation -RGNBSM-. In addition to this, a huge amount of SCR samples from other industrial workplaces have also been analyzed.

This vast experience and the studies carried out in the frame of national and international projects, played a key role in developing methods for the analysis of these hazardous substances, garanting the most accurate assessment of the risks at workplaces. These analysis can be undertaken in order to determine not only quartz but also any other crystalline silica phases.

Spanish Regulations establish that National Institute for Silicosis analysis procedures can be considered as reference methods or standards. These procedures have been published and the document can be consulted here (only in Spanish).

Dust in sampling supports

Our lab undertakes gravimetric analysis of dust (respirable, inhalable and thoracic fractions) on a variety of sampling supports.

Respirable crystalline silica in sampling supports

For analyzing respirable crystalline silica in PVC filters, the National Institute for Silicosis lab has developed methods based on Infrared Spectroscopy (FTIR) and X-ray Diffraction (XRD).

The analysis of samples if different crystalline silica phases may be present (quartz, cristobalite or tridymite) can be carried out by XRD.