Date of Graduation
Statler College of Engineering and Mineral Resources
Industrial and Managements Systems Engineering
Eun Gyung (Emily) Lee
Dr Douglas Boyer
Continuing concern about exposure to respiratory hazards at various workplaces and prevalent pandemics such as H1N1/09 influenza and COVID-19, have necessitated a need for more research regarding respirators. Quantitative fit testing (QNFT) is a critical component of an OSHA compliant respiratory protection program. QNFTs are often performed in environments where temperature and relative humidity (RH) vary. However, no study has investigated the possible effects of these parameters on penetration and QNFT results.
This comparative study utilized condensation nuclei counter (CNC) and controlled negative pressure (CNP) methods to quantitatively determine simulated mannequin fit factors (SMFFs) and human fit factor (HFFs) using 8 different models of NIOSH-certified elastomeric respirators in laboratory ambient and controlled environmental conditions. Each test methodology employed 8 test subjects, 2 QNFT methods, two environmental conditions and 8 respirator models resulting in 32 overall fit factors (FF) for each subject. This resulted in a total of 256 FFs collected on human subjects and 96 FFs for a mannequin. The SMFFs determined by CNC, were measured at 14 breaths per minute (bpm) and tidal volume (VT) of 800mL (11.2LPM) at cyclic breathing pattern.
A paired t-test using SAS PROC means, revealed that the mean FF measured with the CNC test methodology, was significantly different to the mean CNP FF (p0.05). The comparison of the mean SMFF and the mean HFF using the SAS procedure GLM showed no significant difference in either ambient or controlled environmental conditions (all p>0.05). Significant differences were seen in all the variables (device type, condition, respirator style and respirator make) in the four-factor model with post hoc analyses for the mannequin study but only the “device type” and “respirator make” produced significant differences in the human subjects study. The results indicated that the comparison of the mannequin and human tests results could be beneficial in conducting respiratory protection research.
Fadairo, Olanrewaju John, "Comparison of Condensation Nuclei Counter and Controlled Negative Pressure Methods under Different Environmental Conditions Tested with a Mannequin and Human Subjects" (2020). Graduate Theses, Dissertations, and Problem Reports. 7986.