Silica Measurement with High Flow Rate Respirable Size Selective Samplers: A Field Study

Abstract

High and low flow rate respirable size selective samplers including the CIP10-R (10 l min−1), FSP10 (11.2 l min−1), GK2.69 (4.4 l min−1), 10-mm nylon (1.7 l min−1), and Higgins-Dewell type (2.2 l min−1) were compared via side-by-side sampling in workplaces for respirable crystalline silica measurement. Sampling was conducted at eight different occupational sites in the USA and five different stonemasonry sites in Ireland. A total of 536 (268 pairs) personal samples and 55 area samples were collected. Gravimetric analysis was used to determine respirable dust mass and X-ray diffraction analysis was used to determine quartz mass. Ratios of respirable dust mass concentration, quartz mass concentration, respirable dust mass, and quartz mass from high and low flow rate samplers were compared. In general, samplers did not show significant differences greater than 30% in respirable dust mass concentration and quartz mass concentration when outliers (ratio <0.3 or >3.0) were removed from the analysis. The frequency of samples above the limit of detection and limit of quantification of quartz was significantly higher for the CIP10-R and FSP10 samplers compared to low flow rate samplers, while the GK2.69 cyclone did not show significant difference from low flow rate samplers. High flow rate samplers collected significantly more respirable dust and quartz than low flow rate samplers as expected indicating that utilizing high flow rate samplers might improve precision in quartz measurement. Although the samplers did not show significant differences in respirable dust and quartz concentrations, other practical attributes might make them more or less suitable for personal sampling.

Calibration of high flow rate thoracic-size selective samplers

“…[5] Another high flow respirable size selective cyclone, the FSP10, was tested at the National Institute for Occupational Safety and Health (NIOSH) where it showed similar performance to other commonly used respirable size selective samplers. [1–3,6] Like the GK2.69 cyclone, these two high flow rate cyclones might be used for dual fraction size selective sampling to measure the respirable and thoracic-size fractions. Therefore, NIOSH and the Health Safety Laboratory (HSL) carried out work to determine the flow rate at which the cyclone’s penetration characteristics most closely agreed with the thoracic-size convention defined by the American Conference of Governmental Industrial Hygienists (ACGIH) [7] /Comité Européen de Normalisation (CEN) [8] /International Standards Organization (ISO).…”

Laboratory comparison of new high flow rate respirable size-selective sampler

“…[1] The new standards include the statement that “the employer shall ensure that no employee is exposed to an airborne concentration of RCS in excess of 50 μ g/m 3 , calculated as an 8-hr time-weighted average (TWA) exposure and employee exposure will remain below 25 μ g/m 3 as an 8-hr TWA under any foreseeable conditions.” The performances of respirable size-selective samplers operating at a higher flow rate (>4L/min) than traditional samplers (1.7 or 2.2 L/min flow rate) have been evaluated. [2–6] These are designed to collect more respirable dust for more accurate exposure assessment due to an unacceptable level of variation in low loading RCS samples and are included in the revised National Institute for Occupational Safety and Health (NIOSH) Manual of Analytical Methods for quartz measurement [7,8] as well as the Methods for the Determination of Hazardous Substances guidance document 101/2 (Health and Safety Executive). [9] …”