A New Miniature Respirable Sampler for In-mask Sampling: Part 2—Tests Performed Inside the Mask

Abstract

This paper is the second in a series of two describing the performance of a miniature and low-weight respirable sampler designed to fit inside filtering facepiece (FFP) and half-mask type respirators. The first paper described the design of the miniature sampler and evaluated the particle and collection performance of the miniature sampler. This paper assesses its comparability with the traditional inward leakage measurement technique, and its safe use. Simultaneous mass measurements of a respirable sodium chloride aerosol were taken inside a total inward leakage chamber by a miniature sampler and by sodium flame photometry. Direct side-by-side comparison of the two methods yielded excellent correlation (R = 0.99), as did comparison when sampling from inside four different masks when worn by a breathing Sheffield dummy head. In addition, comparison tests were carried out using three models of FFP worn by human volunteers both with and without the miniature sampler, in order to test whether or not the presence of the miniature sampler negatively affected the protection offered. The difference between the tests carried out with the miniature sampler and without the miniature sampler was not statistically significant (P = 0.3). In all cases, the masks performed within their protection class, whether the miniature sampler was fitted or not. We therefore conclude that the miniature sampler does not significantly affect the protection offered by the masks. The miniature sampler may prove a viable option for in-mask measurements of respirable dust where low air concentrations of hazardous material are expected.

A Physical Analog to Assess Surgical Face Mask Air Flow Resistance During Tidal Ventilation

“…The model described here resembles the Sheffield dummy head that has been developed for the validation of filtering face pieces and respirators in the context of airway protection of workers in dusty environments ( Mogridge et al, 2016 ). To the best of our knowledge, the standard testing for tissue face mask breathability measures the pressure drop across a given tissue surface area, while a constant air flow is passed through ( Konda et al, 2020 ; Zangmeister et al, 2020 ; Cortes et al, 2021 ; Forouzandeh et al, 2021 ).…”

A New Miniature Respirable Sampler for In-mask Sampling: Part 1—Particle Size Selection Performance

“…Most mass loadings tested in this work (30–500 μg) far exceed the loading range expected behind a mask (<5 μg), which is the intended application of the miniature sampler, although further work will be needed to investigate the performance limitations of the miniature sampler if used for routine workplace aerosol sampling. The next phase of the work will compare the performance of the miniature sampler with the techniques used in laboratory-based protection factor studies for RPE and the safety of the device in volunteer studies (Mogridge et al , 2016). This will also provide the opportunity to further compare the collection performance of the miniature sampler with currently accepted quantitative performance assessment methods for inward leakage in RPE.…”

Recent advances in facemask devices for in vivo sampling of human exhaled breath aerosols and inhalable environmental exposures

“… Environmental exposures Analytes Types of facemasks limits of detection Analytical approaches Ref. Chemicals in facemask 16 organophosphate esters Surgical facemasks, self-filtering masks, re-usable facemasks 0.005-0.644 ng/mask LC-MS [ 86 ] Phthalate esters 12 surgical facemask and four N95/P1/P2 facemasks 0.016-10 ng/sample GC-MS [ 89 ] Alkanes, polycyclic aromatic hydrocarbons, phthalate esters, and reactive carbonyls 60 commercial facemasks 0.05-24.9 ng GC/MSD, LC-FID, LC-MS [ 91 ] 31 fluorescent whitening agents 18 brands of children facemasks 0.002 ∼ 10 mg/kg LC-MS [ 92 ] volatile chemicals KN95 facemask NA GC-MS [ 95 ] 12 high-risk volatile chemicals 60 mask samples of different brands 0.23 mg/kg GC-MS [ 96 ] Pollutants in ambient air CO, CO 2 , benzene, HCN, HCl, H 2 SO 4 , HF, acrolein, CH 4 , formaldehyde and PNAs Self-contained breathing apparatus facepiece 5 μg m -3 FT-IR [ 98 ] ∼ 1 ppm Dust and crystalline silica FFP3 facemasks with a miniature sampler 30-500 μg XRD [ 99 ] Sodium chloride aerosol 3 FFP3 facemasks and one half-mask fitted with P3 filters 0.3 μg SFP [ 100 ] 9 PAHs Fabric facemasks 0.06-0.8 ng LC-FLD [ 101 ] ...…”