Ziqing Zhuang

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During July 1995 the National Institute for Occupational Safety and Health (NIOSH) began to certify nine new classes of particulate respirators. To determine the level of performance of these respirators, NIOSH researchers conducted a study to (1) measure the simulated workplace performance of 21 N95 respirator models, (2) determine whether fit-testing(More)
A recent study was conducted to compare five fit test methods for screening out poor-fitting N95 filtering-facepiece respirators. Eighteen models of NIOSH-certified, N95 filtering-facepiece respirators were used to assess the fit test methods by using a simulated workplace protection factor (SWPF) test. The purpose of this companion study was to investigate(More)
The objective of this study was to better understand the benefit of the user seal check step for respirator test subjects in the N95 filtering facepiece respirator donning process. To qualify for the study, subjects were required to pass a standard quantitative fit test on at least one of the three N95 filtering facepiece respirator models: 3M 1860 (cup),(More)
The National Institute for Occupational Safety and Health is conducting a first-of-its-kind study that will assess respirator fit and facial dimension changes as a function of time and improve the scientific basis for decisions on the periodicity of fit testing. A representative sample of 220 subjects wearing filtering-facepiece respirators (FFR) will be(More)
As a continuation of recent studies to assess the accuracy of existing fit test methods, a multi-donning approach to fit testing is presented. As an example of that approach, a multi-donning quantitative fit test for filtering-facepiece respirators is presented and analyzed by comparing its error rates with those of the single-donning approach of current(More)
The National Institute for Occupational Safety and Health (NIOSH), recognizing the difficulties inherent in using old military data to define modern industrial respirator fit test panels, recently completed a study to develop an anthropometric database of the measurements of heads and faces of civilian respirator users. Based on the data collected, NIOSH(More)
BACKGROUND Millions of people rely on N95 filtering facepiece respirators to reduce the risk of airborne particles and prevent them from respiratory infections. However, there are no respirator fit testing and training regulations in China. Meanwhile, no study has been conducted to investigate the fit of various respirators. The objective of this study was(More)
Three fit test methods (Bitrex, saccharin, and TSI PortaCount Plus with the N95-Companion) were evaluated for their ability to identify wearers of respirators that do not provide adequate protection during a simulated workplace test. Thirty models of NIOSH-certified N95 half-facepiece respirators (15 filtering-facepiece models and 15 elastomeric models)(More)