Comparison of Simulated Workplace Protection Factors Offered by N95 and P100 Filtering Facepiece and Elastomeric Half-Mask Respirators against Particles of 10 to 400 nm

Abstract

This study compared the simulated workplace protection factors (SWPFs) between NIOSH-approved N95 respirators and P100 respirators, including two models of filtering facepiece respirator (FFR) and two models of elastomeric half-mask respirator (EHR), against sodium chloride particles (NaCl) in a range of 10 to 400 nm.Twenty-five human test subjects performed modified OSHA fit test exercises in a controlled laboratory environment with the N95 respirators (two FFR models and two EHR models) and the P100 respirators (two FFRs and two EHRs). Two Scanning Mobility Particle Sizers (SMPS) were used to measure aerosol concentrations (in the 10–400 nm size range) inside (Cin) and outside (Cout) of the respirator, simultaneously. SWPF was calculated as the ratio of Cout to Cin. The SWPF values obtained from the N95 respirators were then compared to those of the P100 respirators.SWPFs were found to be significantly different (P<0.05) between N95 and P100 class respirators. The 10th, 25th, 50th, 75th and 90th percentiles of the SWPFs for the N95 respirators were much lower than those for the P100 models. The N95 respirators had 5th percentiles of the SWPFs > 10. In contrast, the P100 class was able to generate 5th percentiles SWPFs > 100. No significant difference was found in the SWPFs when tested against nano-size (10 to 100 nm) and large-size (100 to 400 nm) particles.Overall, the findings suggest that the two FFRs and two EHRs with P100 class filters provide better performance than those with N95 filters against particles from 10 to 400 nm, supporting current OSHA and NIOSH recommendations.

A framework for comparing N95 and elastomeric facepiece respirators on cost and function for healthcare use during a pandemic- A literature review

“… - Product. Costs -Fit test costs - Continuous use of N95s - Fit testing vs no fit testing – – - Costs and factors may not be similar across countries [ 30 ] - UV disinfection system – - UV penetration - Disinfection – – - Layer disinfection does not reflect reality [ 3 ] - Filtration efficiency testing – - Filtration protection - Patient care interference – - Testing with low pressure drop for breathing - Testing was limited to two bacteria [ 41 ] - Randomized simulated workplace study – - Fit test - Effect on attention - Muffled speech - Difficulty hearing - Dizziness - Fatigue -Breathing -Skin irritation - Other costs and market considerations impact respirator adoptability [ 17 ] - Quantitative fit test - Ambient air particle concentration measurements – - Face seal leakage and fit testing – -Workload induced heavy breathing - Need for frontline workers investigation [ 9 ] - Simulated workplace protection factor testing - Facial measurements - Sex-stratified analysis – - Face seal leakage and fit testing – – - Only considers respirator and facial dimensions as design factors …”

“…In this regard, EFRs have an advantage due to more adjustable components as highlighted by Zhuang et al. [ 9 ]. Perhaps, APFs should be based not only on the type of mask and mask size, but typical duration of use before leakage.…”

“…For further discussion on the relative particulate filtering performance of these respirators see Zhuang et al. [ 9 ] who compared P100 filtered EFRs with N95s in a simulated workplace. Zhuang found that EFRs with P100 filters performed better than N95s potentially due to better fit given that EFRs have adjustable head straps.…”

The impact of extreme reuse and extended wear conditions on protection provided by a surgical-style N95 filtering facepiece respirator

“…Later studies (Sietsema et al 2015, Sietsema andBrosseau (2018) showed a good correlation between FFs and the SWPF result (measuring face seal leakage only) when the respirator was not doffed in between. He et al (2015) measured the SWPF performance of N95 and P100 filtering facepiece and elastomeric halfmask respirators when challenged with an aerosol in two particle size ranges, with no difference found. Or et al (2016) and Wu (2018) measured real-time face seal leakage for different models of N95 respirators using optical particle counting-based instruments, with Or et al finding an instantaneous PF of less than 10 more frequently in nurses performing moving exercises with heavy activity, in clinical settings.…”