381b - Advancements in the measurement for respirable crystalline silica to improve the determination of worker’s personal exposures

This presentation will discuss the work conducted at the Health and Safety Executive’s (HSE) science and research centre over the last 10 years and the advantages and limitations of new developments for the measurement of workers’ personal exposures to respirable crystalline silica (RCS). HSE has investigated and evaluated new measurement technologies for determining RCS exposures more accurately at lower concentrations (below the workplace exposure limit) where there remains a risk of respiratory ill health. It is estimated that 560,000 workers are potentially exposed to aerosols containing RCS in the United Kingdom, which can cause debilitating lung diseases like silicosis and cancer. Measurement science is undergoing a period of technological development. Current research focuses include, use of new sensitive Raman instrumentation, the miniaturisation of instruments and ability to provide RCS measurements on-site (without the need for laboratory analysis), and computational methods to improve RCS quantification when mineral interferences are present. These options have enabled us to improve the measurement of RCS in the laboratory and provide end-of-shift personal RCS exposures. For example, HSE have demonstrated that Raman instrumentation can give limits of detection that are potentially low enough (~200 ng) to measure RCS in samples collected from behind respirators. In addition, chemometric programmes were shown to improve the accuracy of Fourier transform infrared (FTIR) analysis for RCS measurement when mineral interference is present. Although each approach has benefits, the latter, i.e., on-site portable FTIR instruments with chemometric methods, may offer an overall practical improvement when monitoring workers personal exposures to RCS. Crown copyright (2024)