Continuous fixed-point air sampling performed in the foaming hall and cutting areas over the 1-year study period showed that airborne TDI concentrations were low, below the limit of detection (LOD) of 0.1 ppb in over 87% of the air recordings obtained in the cutting areas and over 95% of the readings from the foaming hall. Over the entire 12-month study period, the maximum TDI vapor concentration recorded was 10.0 ppb in the foaming hall and 5.4 ppb in the cutting area, and no air sampling period exceeded the threshold limit value (TLV) for a 8-hr workday assigned by the American Conference of Governmental Industrial Hygienists (ACGIH) for TDI (5.0 ppb; 36 ug NCO/m3), the occupational exposure limit used in the United Kingdom, and many European countries[Bello, et al. 2004]. The peak exposures recorded were also below the Permissible Exposure Limit (PEL) ceiling for TDI (20 ppb) set by the Occupational Safety and Health Administration (OSHA)[Bello, et al. 2004]