Filter Efficiency of Typical Respirator Filters for Nanoscale Particles

Project Information

Principal Investigator	David Pui
Institution	University of Minnesota
Project URL	View
Relevance to Implications	High
Class of Nanomaterial	Generic
Impact Sector	Human Health
Broad Research Categories	Exposure Safety Control
NNI identifier

Funding Information

Country	USA
Anticipated Total Funding	n/a
Annual Funding	n/a
Funding Source	NIOSH
Funding Mechanism	Intramural
Funding Sector	Government
Start Year	2005
Anticipated End Year	2006

Abstract/Summary

Manufactured nanoparticles may exist as separate particles of only a few nanometers. Respirator theory predicts that as particle size decreases from 300 nm, diffusion becomes increasingly effective in capturing the particles on the filter filters. However, a recent study suggests that as particles reach sizes of a few nanometers, capture efficiency begins to decline. The goals of this project are to determine (1) whether single-fiber filtration theory is valid for engineered nanoparticles, (2) the possible boundaries of the most penetrating particle size range, and (3) the filtration boundaries of nanosized particles in the diffusional capture mechanism range. The findings from this study will enable the extension of single fiber theory beyond the traditionally described particle range. These findings will also allow NIOSH to make recommendations regarding the effectiveness of respirator filter media for engineered nanoparticles on the basis of experimental data.