Project title: Respirable Crystalline Silica Exposure In Stone Countertop Fabrication Workers
Completed in: 2021 | Faculty advisor: Martin A. Cohen
Artificial stone countertops are the centerpiece of countless modern kitchen remodels, but the process of fabricating these surfaces has recently gained attention due to high occupational exposures to fine silica dust, known as respirable crystalline silica (RCS). This report summarizes OSHA State Plan health compliance inspections of stone countertop fabricators in King County, WA. This work was done as part of an internship project for the Washington State Department of Labor and Industries (LNI), Division of Occupational Safety and Health (DOSH). Further, possible improvements to exposure controls and administrative processes are presented as a step towards fully protecting workers in this industry from silicosis and other diseases. Over the 14 inspections reviewed by this report, 39% of workers sampled for airborne RCS had exposures above the permissible exposure limit (PEL) of 50 µg/m3 over an 8-hour time weighted average. Workers employed in the role of fabricator had the largest number and highest average RCS exposures, although those in the role of CNC operator had a higher proportion of samples exposed above the PEL. Out of the 20 total employees exposed above the PEL, only 2 wore respiratory protection that was compliant with DOSH standards. The remaining 18 employees were not fully protected from RCS exposure, as even if these employees wore respirators, the devices may not adequately protect them from inhaling dust unless all components of a DOSH-compliant respiratory protection program were followed. Results presented in this study indicate an urgent need education and elimination of the RCS hazards associated with stone countertop fabrication. To improve current conditions, an emphasis should also be placed on regular exposure assessments, implementing compliant respiratory protection programs, and feasible improvements in ventilation systems and engineering controls.