NIOSH logo and tagline

Part 2: Variability of Respirator Fit Test Panels – NIOSH Study Results – Tuesday, August 20, 2013

NIOSH NPPTL Science Webinar

View the video recording of this webinar [21.2M]

View the slide presentation of this webinar [PDF – 1.8M]

Please email Jackie Krah for webinar assistance or call (412)-209-5363.

The purpose of this interactive webinar is to provide further opportunity to discuss the description and results of a NIOSH study assessing the fluctuation between bivariate panels used in respirator fit which was the topic of the July 23, 2013 webinar.

A portion of this webinar will be devoted to discussing the following questions posed by NPPTL during the previous webinar.

  • Is the use of the coefficient of variation an appropriate approach for inter-panel variability analysis? If not, what other approaches are available?
  • Can other analysis methods be applied to the data collected during the NPPTL inter-panel variability study to any other issues/questions regarding inward leakage?
  • What further research and data analysis is needed to answer the question of inter-panel variability?

Participants are encouraged to submit their responses to these questions to Christopher Coffey at by August 9, 2013. The responses will be summarized and discussed during the webinar. All responses and comments received including any personal information provided will be posted without change to NIOSH docket number 250, Development of Inward Leakage Requirements for Half-Mask Air-Purifying Particulate Respirators Approved under Subpart K of 42 CFR Part 84) when available at

Discussion at the August 20 webinar will include further data analysis such as:

  • Within respirator type variability
  • Pass/Fail rate comparisons
  • Within cell and panel variability
  • Use of cell clouds to evaluate “size specific” data
  • New subjects vs. experienced
  • Male/female comparisons
  • Inter-rater statistics for analysis of panel variability

The issues associated with the implementation of new panels into the NIOSH respirator certification program will be examined. These include the current use of the two Los Alamos National Laboratory panels, panel size, and the possible use of the NIOSH Bivariate and PCA panels.

Webinar Presenters

Christopher Coffey, Ph.D. received his B.A. in Chemistry from Mercyhurst College, Erie, PA, M.S. in Occupational Health and Safety Engineering and Ph.D. in Industrial Engineering (Industrial Hygiene) from West Virginia University. He is the Associate Director for Science, National Personal Protective Technology Laboratory, National Institute for Occupational Safety and Health. From 1993 to 2001, Dr. Coffey was involved in the area of respiratory protection, both certification and research. His respirator research was on fit-test methods. He was the first to demonstrate that the results of all fit-test methods did not correlate with a wearer’s actual exposure. His work was also the first to provide a scientifically based explanation of the discrepancies between fit factors and workplace protection factors. He was also the first to characterize the errors (i.e., alpha and beta) associated with the most commonly used fit-test methods. His work also involved determining the fitting characteristics of various types of air-purifying respirators.

Colleen Miller is a Physical Scientist and the Acting Lead, Policy, in the Technology Evaluation Branch of the National Personal Protective Technology Laboratory at the National Institute for Occupational Safety and Health. She joined NIOSH in March of 2008. She has A.A.S. degree from Broome Community College in Chemical Engineering Technology, and B.S. in Polymer Science from the Pennsylvania State University. Prior to joining NIOSH, Colleen worked in applied research and development in direct support of manufacturing processes at Corning, Inc., and as an independent consultant at Matco Associates Inc., specializing in materials characterization and failure analysis. She is currently leading the NOSH effort to develop inward leakage requirements for air-purifying half-mask respirators and the concept for NIOSH certification of air-fed ensembles. Ms. Miller serves as the Assistant Coordinator of the Personal Protective Technology Program Cross-sector, an activity of the National Occupational Research Agenda (NORA).

James (Terry) Wassell, Ph.D. is a statistician in the NIOSH Division of Safety Research Dr. Wassell has 23 years of experience as Research Mathematical Statistician in CDC including award-winning research publications in occupational epidemiology and statistical methods. His educational accomplishments include the Ph.D from The Ohio State University (1989); Master of Applied Statistics degree (1982) and Master of Science (1981) from the Louisiana State University; Bachelor of Science from the University of Pittsburgh (1976). For this project, he developed the experimental design and will perform the data analysis.

This webinar will be available via live meeting. Registration by August 16, 2013 is required and is limited to 200 connections. Groups of interested parties from one location are encouraged to dial in as a group.

Date and Time by Time Zone: Tuesday, August 20, 2013

  • Eastern Time – 1:00 p.m. to 3:00 p.m.
  • Central Time – 12:00 noon to 2:00 p.m.
  • Mountain Time – 11:00 a.m. to 1:00 p.m.
  • Pacific Time – 10:00 a.m. to 12:00 noon