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Stefaniak AB, Bowers LN, Knepp AK, Virji MA, Birch EM, Ham JE, Wells JR, Chaolong Q, Schwegler-Berry D, Friend S, Johnson AR, Martin SB, Qian Y, LeBouf RF, Birch Q, Hammond D. Three-dimensional printing with nano-enabled filaments releases polymer particles containing carbon nanotubes into air. Indoor Air 2018; 28:840-851. [PMID: 30101413 PMCID: PMC6398333 DOI: 10.1111/ina.12499] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 08/03/2018] [Accepted: 08/06/2018] [Indexed: 05/14/2023]
Abstract
Fused deposition modeling (FDM™) 3-dimensional printing uses polymer filament to build objects. Some polymer filaments are formulated with additives, though it is unknown if they are released during printing. Three commercially available filaments that contained carbon nanotubes (CNTs) were printed with a desktop FDM™ 3-D printer in a chamber while monitoring total particle number concentration and size distribution. Airborne particles were collected on filters and analyzed using electron microscopy. Carbonyl compounds were identified by mass spectrometry. The elemental carbon content of the bulk CNT-containing filaments was 1.5 to 5.2 wt%. CNT-containing filaments released up to 1010 ultrafine (d < 100 nm) particles/g printed and 106 to 108 respirable (d ~0.5 to 2 μm) particles/g printed. From microscopy, 1% of the emitted respirable polymer particles contained visible CNTs. Carbonyl emissions were observed above the limit of detection (LOD) but were below the limit of quantitation (LOQ). Modeling indicated that, for all filaments, the average proportional lung deposition of CNT-containing polymer particles was 6.5%, 5.7%, and 7.2% for the head airways, tracheobronchiolar, and pulmonary regions, respectively. If CNT-containing polymer particles are hazardous, it would be prudent to control emissions during use of these filaments.
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Affiliation(s)
| | - Lauren N. Bowers
- National Institute for Occupational Safety and Health, Morgantown, West Virginia
| | - Alycia K. Knepp
- National Institute for Occupational Safety and Health, Morgantown, West Virginia
| | - M. Abbas Virji
- National Institute for Occupational Safety and Health, Morgantown, West Virginia
| | - Eileen M. Birch
- National Institute for Occupational Safety and Health, Cincinnati, Ohio
| | - Jason E. Ham
- National Institute for Occupational Safety and Health, Morgantown, West Virginia
| | - J. R. Wells
- National Institute for Occupational Safety and Health, Morgantown, West Virginia
| | - Qi Chaolong
- National Institute for Occupational Safety and Health, Cincinnati, Ohio
| | | | - Sherri Friend
- National Institute for Occupational Safety and Health, Morgantown, West Virginia
| | - Alyson R. Johnson
- National Institute for Occupational Safety and Health, Morgantown, West Virginia
| | - Stephen B. Martin
- National Institute for Occupational Safety and Health, Morgantown, West Virginia
| | - Yong Qian
- National Institute for Occupational Safety and Health, Morgantown, West Virginia
| | - Ryan F. LeBouf
- National Institute for Occupational Safety and Health, Morgantown, West Virginia
| | - Quinn Birch
- Department of Chemical and Environmental Engineering, College of Engineering and Applied Science, University of Cincinnati, Cincinnati, Ohio
| | - Duane Hammond
- National Institute for Occupational Safety and Health, Cincinnati, Ohio
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Vo E, Zhuang Z, Birch E, Birch Q. Application of direct-reading and elemental carbon analysis methods to measure mass-based penetration of carbon nanotubes through elastomeric half-face and filtering facepiece respirators. Aerosol Sci Technol 2016; 50:1044-1054. [PMID: 28603336 PMCID: PMC5464732 DOI: 10.1080/02786826.2016.1216519] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Accepted: 07/17/2016] [Indexed: 05/05/2023]
Abstract
The aim of this study was to apply a direct-reading aerosol instrument method and an elemental carbon (EC) analysis method to measure the mass-based penetration of single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs) through elastomeric half-mask respirators (EHRs) and filtering facepiece respirators (FFRs). For the direct-reading aerosol instrument method, two scanning mobility particle sizer/aerodynamic particle sizer systems were used to simultaneously determine the upstream (outside respirator) and downstream (inside respirator) test aerosols. For the EC analysis method, upstream and downstream CNTs were collected on filter cassettes and then analyzed using a thermal-optical technique. CNT mass penetrations were found in both methods to be within the associated efficiency requirements for each type and class of the respirator models that were tested. Generally, the penetrations of SWCNTs and MWCNTs had a similar trend with penetration being the highest for the N95 EHRs, followed by N95 FFRs, P100 EHRs, and P100 FFRs. This trend held true for both methods; however, the CNT penetration determined by the direct-reading aerosol instrument method (0.009-1.09% for SWCNTs and 0.005-0.21% for MWCNTs) was greater relative to the penetration values found through EC analysis method (0.007-0.69% for SWCNTs and 0.004-0.13% for MWCNTs). The results of this study illustrate considerations for how the methods can be used to evaluate penetration of morphologically complex materials through FFRs and EHRs.
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Affiliation(s)
- Evanly Vo
- National Institute for Occupational Safety and Health, National Personal Protective Technology Laboratory, Pittsburgh, Pennsylvania, USA
| | - Ziqing Zhuang
- National Institute for Occupational Safety and Health, National Personal Protective Technology Laboratory, Pittsburgh, Pennsylvania, USA
| | - Eileen Birch
- National Institute for Occupational Safety and Health, Division of Applied Research and Technology, Cincinnati, Ohio, USA
| | - Quinn Birch
- National Institute for Occupational Safety and Health, Division of Applied Research and Technology, Cincinnati, Ohio, USA
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