Abstract
The performances of nine personal continuous monitors (PCMs) were evaluated in dynamically generated toluenediisocyanate (TDI) atmospheres at two concentrations (29.6 and 15.4 ppb, time-weighted averages) and at five relative humidities (RHs). PCMs and a modified Occupational Safety and Health Administration coated-filter reference method concurrently measured the concentrations of the various TDI atmospheres generated. Compared with the reference method, the PCMs generally underestimated the higher TDI concentration at higher humidities (PCM readings ranged from ≈85 to 40% of the reference, at 60 to 80% RHs, respectively). The lower TDI concentration was underestimated by a wider margin by the PCMs (≈70 to 25% of the reference, at 60 to 80% RHs, respectively). There were significant inter-PCM differences when measuring simultaneously the same atmosphere with constant TDI concentration.