Nanoparticle Emission Assessment Technique (NEAT) for the Identification and Measurement of Potential Inhalation Exposure to Engineered Nanomaterials—Part B: Results from 12 Field Studies

Abstract

The National Institute for Occupational Safety and Health (NIOSH) conducted field studies at 12 sites using the Nanoparticle Emission Assessment Technique (NEAT) to characterize emissions during processes where engineered nanomaterials were produced or used. A description of the NEAT appears in Part A of this issue. Field studies were conducted in research and development laboratories, pilot plants, and manufacturing facilities handling carbon nanotubes (single-walled and multi-walled), carbon nanofibers, fullerenes, carbon nanopearls, metal oxides, electrospun nylon, and quantum dots. The results demonstrated that the NEAT was useful in evaluating emissions and that readily available engineering controls can be applied to minimize nanomaterial emissions.

Keywords:

• emissions
• exposure assessment
• nanoparticle
• nanotechnology
• particle number concentration

ACKNOWLEDGEMENTS

The authors wish to gratefully acknowledge the support and encouragement of Paul A. Schulte, manager of the NIOSH Nanotechnology Cross-Sector Program, and John Howard, director of NIOSH. Special appreciation is extended to M. Eileen Birch, Keith Crouch, Brian Curwin, Kevin H. Dunn, Douglas Evans, Mark Hoover, Bon-Ki Ku, Aleksandr Stefaniak, and Paul A. Baron for their consultative expertise. Partial support for this research was provided by NIEHS through Interagency Agreement No. 1-ES-9026-01.

The findings and conclusions in this report are those of the authors and do not necessarily represent the views of the National Institute for Occupational Safety and Health.

Notes

^A Measured number concentrations have been background-adjusted by subtraction.

^B Total carbon values have been background-adjusted. The limit of detection for Total Carbon is 8 μ g. Results are for source-specific sampling unless otherwise noted.

^C PBZ samples collected using an inhalable aerosol sampler with a cut size of 100μ m.

^D CPC not used because background particle number concentration exceeded upper limit of instrument.

^A Measured number concentrations have been background-adjusted by subtraction.

^A Measured number concentrations have been background-adjusted by subtraction.

^B Unidentified source of particulate in the size range of 300–500 nm may have contributed to the elevated background particle number concentration.