Toward standardized test methods to determine the effectiveness of filtration media against airborne nanoparticles

Abstract

The filtration of airborne nanoparticles is an important control technique as the environmental, health, and safety impacts of nanomaterials grow. A review of the literature shows that significant progress has been made on airborne nanoparticle filtration in the academic field in the recent years. We summarize the filtration mechanisms of fibrous and membrane filters; the air flow resistance and filter media figure of merit are discussed. Our review focuses on the air filtration test methods and instrumentation necessary to implement them; recent experimental studies are summarized accordingly. Two methods using monodisperse and polydisperse challenging aerosols, respectively, are discussed in detail. Our survey shows that the commercial instruments are already available for generating a large amount of nanoparticles, sizing, and quantifying them accurately. The commercial self-contained filter test systems provide the possibility of measurement for particles down to 15 nm. Current international standards dealing with efficiency test for filters and filter media focus on measurement of the minimum efficiency at the most penetrating particle size. The available knowledge and instruments provide a solid base for development of test methods to determine the effectiveness of filtration media against airborne nanoparticles down to singledigit nanometer range.

Carbon Nanotube Penetration Through Fiberglass and Electret Respirator Filter and Nuclepore Filter Media: Experiments and Models

“…Table 1 also shows the parameters of the 1 mm pore diameter Nuclepore filter (WHA-111112, GE Healthcare Biosciences, Pittsburgh, PA, USA) that was used to study the mechanical deposition mechanisms of the MWCNTs. Figure 1 shows the experimental setup for the MWCNT generation and penetration tests, in which the atomization and electrostatic classification techniques were used to produce monodisperse MWCNTs (Wang and Tronville 2014). Polydisperse MWCNTs were first generated by atomizing 0.002 wt% functionalized MWCNTs solution using the homemade nebulizer as mentioned earlier.…”

Filtration Performance Against Nanoparticles by Electrospun Nylon-6 Media Containing Ultrathin Nanofibers

“…The filter testing system was similar to that the previous studies of Kim et al (2007) and Wang et al (2007) and Wang and Tronville (2014) capable of tests using 15-450 nm NaCl particles. NaCl particles were generated by an atomizer aerosol generator (TSI 3079, TSI Inc., Shoreview, MN, USA) and classified by a differential mobility analyzer (DMA, TSI 3081, TSI Inc., Shoreview, MN, USA).…”

Inter-Laboratory Validation of the Method to Determine the Filtration Efficiency for Airborne Particles in the 3-500 nm Range and Results Sensitivity Analysis

“…(Wang and Tronville, 2014). An atomizer was used to generate airborne Di(2-ethylhexyl) sebacate (DEHS) or Di(2-ethylhexyl) phthalate (DEHP) particles in the size range of 10-500 nm.…”

“…Therefore, it was important to establish correlation ratios by performing the measurement without any filter medium in the filter holder. Then the filtration efficiency was measured with the filter placed inside the holder and calculated according to Wang and Tronville (2014).…”

“…Filtration of airborne nanoparticles is crucial due to the increased produced quantities from material synthesis and combustion emissions (Wang and Tronville, 2014). More small particles are being produced compared to the past due to the blossom of the field of nanotechnology.…”