Asbestos Exposures During Routine Floor Tile Maintenance. Part 1: Spray-Buffing and Wet-Stripping

Abstract

Abstract This study was conducted to evaluate airborne asbestos concentrations during spray-buffing and wet-stripping of asbestos-containing resilient floor tile under three levels of floor condition (poor, medium, and good). Airborne asbestos concentrations were measured by transmission electron microscopy (TEM) before and during each floor care maintenance procedure in the breathing zone of the custodial personnel. Airborne total fiber concentrations were also measured by phase contrast microscopy (PCM) for comparison with the Occupational Safety and Health Administration (OSHA) permissible exposure limit (PEL) of 0.1 f/cm3, 8-hour time-weighted average. This study demonstrates that routine spray-buffing and wet-stripping of asbestos-containing resilient floor tile can result in elevated levels of airborne asbestos. Greater releases of airborne asbestos were observed during wet-stripping than during spray-buffing. The results of this study further suggest that multiple layers of sealant applied to the floor prior to the application of the floor finish can reduce the release of asbestos fibers during removal of the finish. Approximately 98.6 percent of the asbestos structures measured were < 5 μm in length and would not be detected or counted by PCM analysis. The PCM results suggest that the OSHA PEL would not be reached during typical floor care maintenance operations, but the TEM analyses clearly show that elevated levels of airborne asbestos are present in the breathing zones of custodial personnel. Operation and maintenance programs should address the potential asbestos exposure hazards posed by routine floor tile maintenance activities.