Experimental evaluation of personal protection devices against graphite nanoaerosols: fibrous filter media, masks, protective clothing, and gloves

Abstract

<jats:p> In this study, different conventional personal protection devices (fibrous filters, cartridges for respirators, protective clothing, and gloves) well qualified for micron particles were tested with graphite nanoparticles ranging from 10 to 100 nm (electrical mobility diameter). For this purpose, two specific test benches were designed: one for filter-based devices which are tested under a controlled air flow and other for gloves and protective clothing based on the “through diffusion method.” The penetration versus particle size shows for most tested filter media the behavior predicted by the theoretical Brownian capture: penetration decreases when particle diameter decreases. No thermal rebound was detected until 10 nm for graphite nanoparticles. Protective clothes were tested by two methods and same trends were obtained. Nonwoven fabrics (air-tight materials) are much more efficient against nanoparticles than cotton and paper. Gloves tested by “through diffusion technique,” in static condition seem to efficiently protect against graphite nanoparticles in spite of their important porosity. </jats:p>

An Overview of Airborne Nanoparticle Filtration and Thermal Rebound Theory

“…Silver particles: 3 nm < dp < 20 nm NaCl particles: 15 nm < dp < 400 nm Rengasamy et al, 2008 Silver particles: 4 nm < dp < 30 nm NaCl particles: 20 nm < dp < 400 nm N95 and P100 filter Q = 85 lpm Nano DMA UCPC Silver particles: 3 nm < dp < 20 nm Stainless steel wire screen df = 90 μm T < 500 K UCPC Nano DMA No thermal rebound Golanski et al, 2009 Graphite particles: 10 nm < dp <100 nm Carbon, NaCl, copper particles: 5 nm < dp < 400 nm NaCl particles: 10 nm < dp < 60 nm Wire screen df = 30, 60, 2.1, 9.5 μm α = 0. 215, 0.276, 0.088, 0.172 L = 0.06, 0.12, 0.38, 0.28 mm…”

“…Particles below these sizes were not tested for (Huang et al, 2007;Japuntich et al, 2007;Kim et al, 2007;Steffens and Coury, 2007;Wang et al, 2007;Rengasamy et al, 2008;Shin et al, 2008). In 2009, Golanski et al (2009) filtered out graphite particles in the range of 10 nm to 100 nm through a fibrous and electret filter, with the filtration efficiency measured by SMPS showing no thermal rebound effect. In the same year, Van Gulijk et al (2009) measured the nanoparticle removal efficiency of a variety of electrically neutral particles (NaCl, CaCl 2 , (NH 4 ) 2 SO 2 , and NiSO 4 ) with diameters ranging from 7 nm to 20 nm passed through a stainless steel screen.…”

Conceptual model for assessment of inhalation exposure to manufactured nanoparticles

“…The MPPS varies with type of filter media and the condition of the respirator (Shaffer and Rengasamy, 2009), especially for electrostatically charged filter media (observed range 30-100 nm). Other studies confirmed that these types of filters are less effective for nanoparticles compared with HEPA or ULPA-type of filters (Golanski et al, 2009). Evaluation of commercial filter media under harsh conditions, for example, high-face velocity, is needed.…”

The Effectiveness of Specific Risk Mitigation Techniques Used in the Production and Handling of Manufactured Nanomaterials: A Systematic Review

“…Publication bias can be expected but could not be assessed due to lack of data. EHR P100 on manequin without seal [22] EHR P3 and P2 on manequin without seal [23] N95 FFRs [24] N95 FFRs [25] FFR electrostatic filter [26] glass fiber filter [26] FPP3 [29] cloth masks [28] FFR P2, P3 [30] N95 FFRs [31] P100 FFR [31] N95 FFRs [32] PF res (-) 1 10 100 1000 10000 N95 FFRs worn by 12 persons [27] N95 FFRs worn by 25 persons [39] P100 FFRs worn by 25 persons [39] N95 EHRs worn by 25 persons [39] P100 EHRs worn by 25 persons [39] EHR P100 for manequin without seal [22] EHR P3 without seal [23] EHR P2 without seal [23] N95 sealed [25] Electrostatic FPP3 [29] cloth masks [28] N95 FFRs [31] P100 FFRs [31] N95 FFRs [32] N95 FFR (30) FFP2 [30] P100 [30] FFP3 [30] FFR N95 for MWCNT [37] FFR N99 for MWCNT [37] FFR N100 for MWCNT [37] FFR N95 for MWCNT mass [38] FFR N99 for MWCNT mass [38] FFR N100 for MWCNT mass [38] …”

“…3) or total inward leakage (TIL) of the respirators (Gray in Fig. 3) [22][23][24][25][26][27][28][29][30][31][32]. The FFR using an electrostatic filter showed 30 to 70 nm of MPPS.…”