Respirator Probe Bias Evaluation Using the Advanced Headform Respirator Test System

Details

• Personal Author:
  Bergman, Michael ; Brochu E ; Lei Z ; Rizor A ; Zhuang Z
• Description:
  Objective: Our lab has successfully used advanced manikin headforms in several studies to simulate respirator fit on humans. However, sampling probes may yield biased measurements due to imperfect mixing of test agents or streamlining within a respirator. This study used advanced headforms under different test conditions to evaluate factors that affect respirator probe bias in filtering facepiece respirators (FFR) and elastomeric half-mask respirators (EHR). Methods: Three N95 FFR models, one P100 FFR model, and one P100 EHR model were tested on two sizes of static headforms (medium and large) connected to a breathing simulator. Respirators were probed with a flush probe. Three samples of each model were tested. Sodium chloride aerosol was used as the challenge agent. Two PortaCount® units (model: 8038+; TSI, Inc.) were used to measure manikin fit factor (FFman) of the respirator (mask location) and FFman at a location directly downstream of the headform (reference location). Three test conditions were evaluated: 1) cyclic breathing only (CB); 2) cyclic breathing with heated/humidified exhaled air (100% RH, 34.5 +/- 2 C) (H1); and 3) cyclic breathing with heated/humidified exhaled air and heated PortaCount sample lines to reduced humidity condensation (H2). Each test condition was conducted at two different minute ventilations (25 and 40 L/min), each for one minute. Analysis of variance (ANOVA) was used to test independent variables (HF (i.e., headform size), CONDITION, FLOWRATE, CLASS (i.e., N95 or P100), and STYLE (i.e., FFR or EHR) and their interactions for significant effects on probe bias. Duncan's Multiple Range Test was used to test significant differences in mean probe bias for each independent variable. Results: Significant (P < 0.05) variables and interactions were: CLASS, STYLE, CONDITION, HF*STYLE, CONDITION*STYLE, and CONDITION*CLASS. The mean bias for the condition CB (1.2%) was significantly different than H2 and H1 which were 3.2% and 3.6%, respectively. The significantly different mean biases for CLASS were -2.1% and 5.8% for P100 and N95 classes, respectively. The significantly different mean biases for STYLE were -0.1% and 3.5% for EHR and FFR styles, respectively. Conclusions: The test procedures evaluated show small probe bias (< 4%) and may be considered as candidates for developing standardized test methods using advanced headforms. [Description provided by NIOSH]
• Subjects:
  Elastomers Occupational Health Personal Protective Equipment Respiratory Protective Devices Safety
• Keywords:
  Elastomeric Half-mask Respirators Equipment Design Equipment Testing Fit Testing N95 Filtering Facepiece Respirators
• Publisher:
  American Industrial Hygiene Association
• Document Type:
  Text
• Genre:
  Abstract or Summary
• Place as Subject:
  Maryland ; OSHA Region 3 ; Pennsylvania
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  NPPTL - National Personal Protective Technology Laboratory
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  79
• NIOSHTIC Number:
  nn:20066039
• Citation:
  AIHce 2016: American Industrial Hygiene Conference and Exposition Pathways to Progress, May 21-26, 2016, Baltimore, Maryland. Falls Church, VA: American Industrial Hygiene Association, 2016 May; :79
• Contact Point Address:
  M. Bergman, CDC/NIOSH/NPPTL, Pittsburgh, PA
• Federal Fiscal Year:
  2016
• Peer Reviewed:
  False
• Source Full Name:
  AIHce 2016: American Industrial Hygiene Conference and Exposition Pathways to Progress, May 21-26, 2016, Baltimore, Maryland
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:dd927573f22934041c18fce8b3832397d68dd1e892362c81070e24d2fa313c03b2f5bdec2b80203b6d56188bd3783160311f50d7c7758b716e4994b646d3027a
• Download URL:
  https://stacks.cdc.gov/view/cdc/209122/cdc_209122_DS1.pdf
• File Type:
  [PDF - 1.43 MB ]