Evaluation of total inward leakage for NIOSH-approved elastomeric half-facepiece, full-facepiece, and powered air-purifying respirators using sodium chloride and corn oil aerosols.

Recently, total inward leakage (TIL) for filtering facepiece and elastomeric half-mask respirators (EHRs) was measured according to the International Organization for Standardization (ISO) test method standard 16900-1:2014 that showed larger TIL for corn oil aerosol than for NaCl aerosol. Comparison of TIL measured for different aerosols for higher protection level respirators is lacking. The objective of this study was to determine TIL for EHRs, full-facepiece respirators, and loose-fitting and tight-fitting powered air-purifying respirators (PAPRs) using NaCl and corn oil aerosols to compare.

Do industrial N95 respirators meet the requirements to be used in healthcare? - A possible solution to respirator shortages during the next pandemic.

Shortages of surgical N95 respirators (surgical N95 FFRs) can occur during a pandemic. To understand if industrial N95 FFRs have FDA required fluid penetration resistance and flammability, five NIOSH approved N95 models were evaluated using the ASTM F1862 method and flammability using the 16 CFR 1610 method, respectively. Three models passed both fluid penetration resistance and flammability indicating that some N95 models on the market can be used as surgical N95 FFRs during a pandemic.

New technique to evaluate decontamination methods for filtering facepiece respirators.

Background: A major concern among health care experts is a shortage of N95 filtering facepiece respirators (FFRs) during a pandemic. One option for mitigating an FFR shortage is to decontaminate and reuse the devices. The focus of this study was to develop a new evaluation technique based on 3 major decontamination requirements: (1) inactivating viruses, (2) not altering the respirator properties, and (3) not leaving any toxic byproduct on the FFR.

Effects of volume, velocity, and composition on the resistance to synthetic blood penetration of N95 filtering facepiece respirators and other head/facial personal protective equipment.

Surgical N95 filtering facepiece respirators (surgical N95 FFRs) are National Institute for Occupational Safety and Health-approved N95 filtering facepiece respirators (N95 FFRs) cleared by the Food and Drug Administration for resistance to liquid penetration and flammability. A recent study showed that several N95 FFR models performed as well as surgical N95 FFRs in synthetic blood penetration tests that evaluate resistance to penetration by horizontal projection. This aspect, in addition to the influence of other factors on liquid penetration, are not well studied.

Assessment of respirator fit capability test criteria for full-facepiece air-purifying respirators.

An ASTM International subcommittee on Respiratory Protection, F23.65 is currently developing a consensus standard for assessing respirator fit capability (RFC) criteria of half-facepiece air-purifying particulate respirators. The objective of this study was to evaluate if the test methods being developed for half-facepiece respirators can reasonably be applied to nonpowered full-facepiece-air-purifying respirators (FF-APR).

Evaluation of Rigidity of Surgical N95 Respirators Using a Manikin-System: A Pilot Study.

Background: Surgical N95 respirators are devices certified by the National Institute for Occupational Safety and Health (NIOSH) and also cleared by the Food and Drug Administration (FDA) as a medical device. They are commonly used in healthcare settings to provide protection from infectious aerosols, as well as, bodily fluid sprays and splashes. It is hypothesized based on design, some models may change their shape significantly (i.

Flammability of Respirators and other Head and Facial Personal Protective Equipment.

Background: Personal protective equipment (PPE) is worn by workers in surgical settings to protect them and patients. Food and Drug Administration (FDA) clears some PPE (e.g.

A comparison of total inward leakage measured using sodium chloride (NaCl) and corn oil aerosol methods for air-purifying respirators.

The International Organization for Standardization (ISO) standard 16900-1:2014 specifies the use of sodium chloride (NaCl) and corn oil aerosols, and sulfur hexafluoride gas for measuring total inward leakage (TIL). However, a comparison of TIL between different agents is lacking. The objective of this study was to measure and compare TIL for respirators using corn oil and NaCl aerosols.

A comparison of facemask and respirator filtration test methods.

NIOSH published a Federal Register Notice to explore the possibility of incorporating FDA required filtration tests for surgical masks (SMs) in the 42 CFR Part 84 respirator certification process. There have been no published studies comparing the filtration efficiency test methods used for NIOSH certification of N95 filtering facepiece respirators (N95 FFRs) with those used by the FDA for clearance of SMs. To address this issue, filtration efficiencies of "N95 FFRs" including six N95 FFR models and three surgical N95 FFR models, and three SM models were measured using the NIOSH NaCl aerosol test method, and FDA required particulate filtration efficiency (PFE) and bacterial filtration efficiency (BFE) methods, and viral filtration efficiency (VFE) method.

Performance of N95 FFRs Against Combustion and NaCl Aerosols in Dry and Moderately Humid Air: Manikin-based Study.

Objectives: The first objective of this study was to evaluate the penetration of particles generated from combustion of plastic through National Institute for Occupational Safety and Health (NIOSH)-certified N95 filtering facepiece respirators (FFRs) using a manikin-based protocol and compare the data to the penetration of NaCl particles. The second objective was to investigate the effect of relative humidity (RH) on the filtration performance of N95 FFRs.

Methods: Two NIOSH-certified N95 FFRs (A and B) were fully sealed on a manikin headform and challenged with particles generated by combustion of plastic and NaCl particles.

Inward leakage variability between respirator fit test panels - Part II. Probabilistic approach.

This study aimed to quantify the variability between different anthropometric panels in determining the inward leakage (IL) of N95 filtering facepiece respirators (FFRs) and elastomeric half-mask respirators (EHRs). We enrolled 144 experienced and non-experienced users as subjects in this study. Each subject was assigned five randomly selected FFRs and five EHRs, and performed quantitative fit tests to measure IL.

Resistance to synthetic blood penetration of National Institute for Occupational Safety and Health-approved N95 filtering facepiece respirators and surgical N95 respirators.

Background: Surgical N95 filtering facepiece respirators (FFRs), certified by the National Institute for Occupational Safety and Health (NIOSH) as a respirator and cleared by the Food and Drug Administration (FDA) as a surgical mask, are often used to protect from the inhalation of infectious aerosols and from splashes/sprays of body fluids in health care facilities. A shortage of respirators can be expected during a pandemic. The availability of surgical N95 FFRs can potentially be increased by incorporating FDA clearance requirements in the NIOSH respirator approval process.

Respirator Performance against Nanoparticles under Simulated Workplace Activities.

Filtering facepiece respirators (FFRs) and elastomeric half-mask respirators (EHRs) are commonly used by workers for protection against potentially hazardous particles, including engineered nanoparticles. The purpose of this study was to evaluate the performance of these types of respirators against 10-400 nm particles using human subjects exposed to NaCl aerosols under simulated workplace activities. Simulated workplace protection factors (SWPFs) were measured for eight combinations of respirator models (2 N95 FFRs, 2 P100 FFRs, 2 N95 EHRs, and 2 P100 EHRs) worn by 25 healthy test subjects (13 females and 12 males) with varying face sizes.

Protection factor for N95 filtering facepiece respirators exposed to laboratory aerosols containing different concentrations of nanoparticles.

A previous study used a PortaCount Plus to measure the ratio of particle concentrations outside (C out) to inside (C in) of filtering facepiece respirators (FFRs) worn by test subjects and calculated the total inward leakage (TIL) (C in/C out) to evaluate the reproducibility of the TIL test method between two different National Institute for Occupational Safety and Health laboratories (Laboratories 1 and 2) at the Pittsburgh Campus. The purpose of this study is to utilize the originally obtained PortaCount C out/C in ratio as a measure of protection factor (PF) and evaluate the influence of particle distribution and filter efficiency. PFs were obtained for five N95 model FFRs worn by 35 subjects for three donnings (5 models × 35 subjects × 3 donnings) for a total of 525 tests in each laboratory.

A quantitative assessment of the total inward leakage of NaCl aerosol representing submicron-size bioaerosol through N95 filtering facepiece respirators and surgical masks.

Respiratory protection provided by a particulate respirator is a function of particle penetration through filter media and through faceseal leakage. Faceseal leakage largely contributes to the penetration of particles through a respirator and compromises protection. When faceseal leaks arise, filter penetration is assumed to be negligible.

Total inward leakage measurement of particulates for N95 filtering facepiece respirators--a comparison study.

National Institute for Occupational Safety and Health (NIOSH) certified particulate respirators need to be properly fit tested before use to ensure workers' respiratory protection. However, the effectiveness of American National Standards Institute-/Occupational Safety and Health Administration (ANSI-/OSHA)-accepted fit tests for particulate respirators in predicting actual workplace protection provided to workers is lacking. NIOSH addressed this issue by evaluating the fit of half-mask particulate filtering respirators as a component of a program designed to add total inward leakage (TIL) requirements for all respirators to Title 42 Code of Federal Regulations Part 84.

N95-companion measurement of cout/cin ratios for two n95 filtering facepiece respirators and one surgical mask.

A previous study in our laboratory measured the ratio of particle concentration outside (Cout)/inside (Cin) of three N95 filtering facepiece respirator (FFR) models with an N95-Companion and other aerosol instruments using a breathing manikin. Results showed that the Companion measured Cin was contributed by particle penetration through face seal leakage and not through filter media suggesting that the Cout/Cin ratio should be similar for different N95 models at any given leak size. To better understand the phenomenon, the current study analyzed the influence of factors, including filter penetration, resistance, and flow rate on the Companion ratios for two N95 FFR (N1 and N2) and one surgical mask (SM1) models using a manikin.

Nanoparticle filtration performance of filtering facepiece respirators and canister/cartridge filters.

Respiratory protection offered by a particulate respirator is a function of the filter efficiency and face seal leakage. A previous study in our laboratory measured the filter penetration and total inward leakage (TIL) of 20-1000 nm size particles for N95 filtering facepiece respirators (FFRs) using a breathing manikin. The results showed relatively higher filter penetration and TIL value under different leak sizes and flow rates at the most penetrating particle size (MPPS), ∼45 nm for electrostatic FFRs,and ∼150 nm for the same FFRs after charge removal.

Evaluation of the performance of the N95-companion: effects of filter penetration and comparison with other aerosol instruments.

Fit factor is the ratio of the particle concentration outside (C(out)) to the inside (C(in)) of the respirator and assumes that filter penetration is negligible. For Class-95 respirators, concerns were raised that filter penetration could bias fit test measurements. The TSI N95-Companion was designed to overcome this limitation by measuring only 40-60 nm size particles.

Nanoparticle penetration through filter media and leakage through face seal interface of N95 filtering facepiece respirators.

National Institute for Occupational Safety and Health recommends the use of particulate respirators for protection against nanoparticles (<100 nm size). Protection afforded by a filtering facepiece particulate respirator is a function of the filter efficiency and the leakage through the face-to-facepiece seal. The combination of particle penetration through filter media and particle leakage through face seal and any component interfaces is considered as total inward leakage (TIL).

Nanoparticle filtration performance of NIOSH-certified particulate air-purifying filtering facepiece respirators: evaluation by light scattering photometric and particle number-based test methods.

National Institute for Occupational Safety and Health (NIOSH) certification test methods employ charge neutralized NaCl or dioctyl phthalate (DOP) aerosols to measure filter penetration levels of air-purifying particulate respirators photometrically using a TSI 8130 automated filter tester at 85 L/min. A previous study in our laboratory found that widely different filter penetration levels were measured for nanoparticles depending on whether a particle number (count)-based detector or a photometric detector was used. The purpose of this study was to better understand the influence of key test parameters, including filter media type, challenge aerosol size range, and detector system.

Total inward leakage of nanoparticles through filtering facepiece respirators.

Nanoparticle (<100 nm size) exposure in workplaces is a major concern because of the potential impact on human health. National Institute for Occupational Safety and Health (NIOSH)-approved particulate respirators are recommended for protection against nanoparticles based on their filtration efficiency at sealed conditions. Concerns have been raised on the lack of information for face seal leakage of nanoparticles, compromising respiratory protection in workplaces.

Evaluation of the filtration performance of NIOSH-approved N95 filtering facepiece respirators by photometric and number-based test methods.

N95 particulate filtering facepiece respirators are certified by measuring penetration levels photometrically with a presumed severe case test method using charge neutralized NaCl aerosols at 85 L/min. However, penetration values obtained by photometric methods have not been compared with count-based methods using contemporary respirators composed of electrostatic filter media and challenged with both generated and ambient aerosols. To better understand the effects of key test parameters (e.

Simple respiratory protection--evaluation of the filtration performance of cloth masks and common fabric materials against 20-1000 nm size particles.

A shortage of disposable filtering facepiece respirators can be expected during a pandemic respiratory infection such as influenza A. Some individuals may want to use common fabric materials for respiratory protection because of shortage or affordability reasons. To address the filtration performance of common fabric materials against nano-size particles including viruses, five major categories of fabric materials including sweatshirts, T-shirts, towels, scarves, and cloth masks were tested for polydisperse and monodisperse aerosols (20-1000 nm) at two different face velocities (5.

Evaluation of the survivability of MS2 viral aerosols deposited on filtering face piece respirator samples incorporating antimicrobial technologies.

Background: Respiratory protective devices exposed to pathogenic microorganisms present a potential source of transmission of infection during handling. In this study, the efficacy of 4 antimicrobial respirators to decontaminate MS2, a surrogate for pathogenic viruses, was evaluated and compared with control N95 filtering face piece respirators, which did not contain any known antimicrobial components.

Methods: MS2 containing droplet nuclei were generated using a Collison nebulizer and loaded onto respirator coupons at a face velocity of 13.