RR825 - Testing of high flow rate respirable samplers to assess the technical feasibility of measuring 0.05 mg.m-3 respirable crystalline silica

Testing of high flow rate samplers to assess the technical feasibility of measuring 0.05 mg.m-3 respirable crystalline silica.

This report describes testing of five personal respirable dust samplers operating with flow rates of 4 l/min or greater, available in 2008. Three were commercially available, one a prototype and one adapted at HSL to operate at a higher flow rate. Testing compared these samplers with a reference sampler, operating at 2.2 l/min, to ascertain if an increase in the mass of dust sampled could improve the reliability of measurements of respirable crystalline silica (RCS). None of the samplers satisfied all of the success criteria for the project, which included, the ability to maintain the specified flow rate over 4-hours, ease of use in the workplace, and an improvement in the measurement precision without additional complications caused by the increased mass of sampled dust. Infrared analysis is not recommended for samples with dust mixtures, because it was difficult to obtain a reliable result when the loading exceeds 1 mg. The samplers with the best performance were the PGP10 and the modified GK2.69 samplers. The other samplers tested either under-sampled or there was lost sample during transfer onto the analysis filter. When field tests were conducted, air sampling pumps operating with the modified GK2.69 samplers failed to maintain a consistent flow rate, and the PGP 10 samplers were heavy and caused discomfort for the workers The report recommends the use of the PGP 10 and GK2.69 samplers after further work to resolve the minor issues and changes in the sampling and measurement strategies to accommodate new procedures for use of higher flow rate samplers.

This report and the work it describes were funded by the Health and Safety Executive (HSE). Its contents, including any opinions and/or conclusions expressed, are those of the authors alone and do not necessarily reflect HSE policy.

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Updated 2021-04-23