73 Performance of Analytical Laboratories Undertaking Silica on Filter Analysis: What Proficiency Testing Data Tells Us

Abstract

Abstract Silicosis, one of the oldest recorded occupational diseases, is a form of lung disease caused by the inhalation of respirable crystalline silica (RCS) within occupational settings such as quarrying, foundries, potteries and stone masonry. Hence worker exposure studies, involving sampling airborne dust onto a filter for subsequent silica analysis in the laboratory, are often conducted. Laboratories use either X-ray diffraction (XRD) or Fourier-Transform Infrared (FTIR) spectroscopy for measurements and follow validated procedures set out in either national regulatory methods or in international consensus standards. But how well do these published methods work in routine occupational hygiene laboratories? The AIR proficiency testing (PT) programme, a partnership between HSE and LGC Standards, offers test items where participants receive samples prepared through the aerosolisation of defined masses of quartz onto air filters. Are there differences between laboratories using direct on filter assays and those that use methods which require a sample preparatory step? Are instrumental measurements by XRD and FTIR comparable? In this presentation, we will attempt to answer these questions using returned PT data.