Celebrating 20 Years of Research: Highlights From NIOSH’s Nanotechnology Research Center’s Field Studies Team

As the National Institute for Occupational Safety and Health (NIOSH) Nanotechnology Research Center (NTRC) marks its 20th anniversary, we celebrate the groundbreaking work of the Field Studies Team. Organized in 2006, the team began by evaluating potential workplace exposures to engineered nanomaterials. Engineered nanomaterials (those created on purpose and not incidentally) have at least one dimension between 1 and 100 nanometers. One nanometer is extremely small—one millionth of a millimeter. Materials at this tiny scale can have unique properties.

The NTRC Field Studies Team is composed of industrial hygienists and engineers and has performed more than 140 on-site exposure assessments. They evaluate advanced materials and processes in many workplaces ranging from large manufacturers, research and development labs, and government facilities, to schools, libraries, and other non-industrial settings. Their efforts contribute to understanding health and safety risks in emerging industries that use nanomaterials.

Early Challenges and Growth

In the early years, the team faced daunting challenges. At that time, there were no proven sampling or analysis methods for nanomaterials. To improve worker safety and health programs, the team had to gain the trust of companies to allow site visits while protecting trade secrets. The team members had to interpret exposure data and communicate risks without guidance from exposure limits, which did not yet exist for any nanomaterials.

Over time, the NTRC Field Studies Team gained experience through fieldwork and partnerships. Team members explained and demonstrated how NIOSH protects intellectual property. The team compared techniques across materials and settings, allowing team members to standardize assessment approaches. These assessment strategies are documented in resources like the Nanoparticle Emission Assessment Technique (NEAT) and the Nanoparticle Exposure Assessment Technique (NEAT 2.0).

An Expanded Focus

Over the years, the team’s focus shifted from mainly carbon nanotubes and nanofibers to other materials like titanium dioxide and silver nanomaterials. Lately, the team has been studying some newly developed materials:

• Nanocellulose
• Quantum dots
• Boron nitride nanotubes
• Thermoplastic filaments with nanomaterial additives
• Photocatalytic liquid resins
• Powders used in 3D printing

The team has been asked to evaluate these materials in diverse settings, from 3-person labs to massive aerospace companies.

What Happens During a Field Study

When the NTRC Field Studies Team visits a workplace, researchers assess potential exposures from nano-related processes and materials. The team also evaluates control technologies to reduce exposures. A field study can involve these activities:

• Measuring to find out if workers are exposed to harmful vapors, fumes, or particles. The team uses many kinds of tools to do this.
• Evaluating and suggesting ways to keep workers safe from exposure.
• Looking carefully at how work is done to make sure it’s safe.
• Checking the personal protective equipment workers wear, like respirators, to see if it is used correctly.

Benefits to Companies

Companies that ask for a site visit receive on-site expertise from NIOSH free of charge. NIOSH experts evaluate exposures and controls. Companies receive a confidential report with exposure results, control evaluations, and recommendations to improve worker health and safety. Workers who volunteer for personal air sampling get their personal air sampling results confidentially. The final report includes these results, but it does not identify individual workers.

Companies can use these reports to implement best practices and cost-effective controls. For example, one company had multiple team visits as they expanded production and relocated twice. The team gave exposure control recommendations that were incorporated as the company grew. This protected workers throughout the changes.

Benefits to NIOSH

NIOSH and the industry benefit from early hazard identification, risk assessments, and best practices. Here are some examples:

• Collect workplace exposure data which informs lab studies so that they are realistic and applicable to actual working conditions.
• Design and improve controls that prevent and minimize worker exposures.
• Improve risk assessment knowledge and techniques.

Looking Ahead

Materials science is expanding rapidly, outpacing occupational health research. For this reason, the team has extended its reach from focusing on nanomaterials to include any advanced materials and related manufacturing processes. NIOSH describes advanced materials as new or modified substances designed to perform better in at least one way. Although all nanomaterials are advanced, not all advanced materials are nanomaterials. This expanded scope allows the team to evaluate emerging manufacturing processes and products such as biomanufacturing and lithium-ion batteries.

The overall goal is to assist, from an occupational health and safety standpoint, in the timely and responsible development of these emerging technologies.

How to Ask for Help from NIOSH

As the nanotechnology landscape constantly evolves, the NTRC Field Studies Team seeks new partners for assessments. NIOSH welcomes opportunities to provide assistance and protect worker health alongside business goals. Companies interested in a free workplace assessment of nanomaterials or advanced materials can email nano@cdc.gov. To learn more, visit our website: Nanotechnology Field Studies Effort.

CDR Kevin L. Dunn, MS, CIH REHS/RS, DAAS, is senior industrial hygienist of the NTRC Field Studies Team in the Hazard Evaluations and Technical Assistance Branch, Division of Field Studies and Engineering.

Eric Glassford, MS, CIH, is an industrial hygienist on the NTRC Field Studies Team in the Hazard Evaluations and Technical Assistance Branch, Division of Field Studies and Engineering.

Lilia Chen, MS, CIH, is the NTRC coordinator and deputy branch chief of the Emerging Technologies Branch, Division of Science Integration.

This blog is part of a series to commemorate the 20^th anniversary of the Nanotechnology Research Center. Click here for additional blogs in the series and on other nanotechnology topics. 

Products

Information gained from these site visits has resulted in products such as tools, guidance documents, informational fact sheets, peer-reviewed publications, and the establishment of recommended exposure limits. A selection of products is listed below:

Dunn KL, Dunn KH, Hammond D, Lo S. [2020]. Three-dimensional printer emissions and employee exposures to ultrafine particles during the printing of thermoplastic filaments containing carbon nanotubes or carbon nanofibers. J Nanopart Res 22(46), https://doi.org/10.1007/s11051-020-4750-8.

Dunn KL, Hammond D, Menchaca K, Roth F, Dunn KH [2020]. Reducing ultrafine particulate emission from multiple 3D printers in an office environment using a prototype engineering control. J Nanopart Res 22(112), https://doi.org/10.1007/s11051-020-04844-4.

Glassford E, Neu-Baker NM, Dunn KL, Dunn KH [2020]. Exposures during wet production and use processes of nanomaterials: a summary of 11 worksite evaluations. Ind Health 58:467–478, https://doi.org/10.2486/indhealth.2019-0169.

NIOSH [2018]. Characterizing 3D printing emissions and controls in an office environment. NIOSH Science Blog. By Dunn KL, Hammond D, Tyraswski J, Duling M. August 16, https://blogs.cdc.gov/niosh-science-blog/2018/08/16/3d-printing.

NIOSH [2018]. Controlling health hazards when working with nanomaterials: Questions to ask before you start. Poster. By Glassford E, Dunn KL, Dunn KH. Cincinnati, OH: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, DHHS (NIOSH) Publication No. 2018-103, https://doi.org/10.26616/NIOSHPUB2018103.

NIOSH [2020]. 3D printing with filaments: Health and safety questions to ask. Poster. By Glassford E, Dunn KL, Dunn KH, Hammond D, Tyrawski J. Cincinnati, OH: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, DHHS (NIOSH) Publication No. 2020-115, https://www.cdc.gov/niosh/docs/2020-115.

NIOSH [2020]. 3D printing with metal powders: Health and safety questions to ask. Poster. By Glassford E, Dunn KL, Dunn KH, Hammond D, Tyrawski J. Cincinnati, OH: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, DHHS (NIOSH) Publication No. 2020-114. https://doi.org/10.26616/NIOSHPUB2020114.

NIOSH [2021]. Current Intelligence Bulletin 70: Health effects of occupational exposure to silver nanomaterials. By Kuempel E, Roberts JR, Roth G, Dunn KL, Zumwalde R, Drew N, Hubbs A, Trout D, Holdsworth G. Cincinnati, OH: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, DHHS (NIOSH) Publication No. 2021-112, https://doi.org/10.26616/NIOSHPUB2021112.

Vamsi K, Roberts J, Glassford E, Gill R, Friend S, Dunn K, Erdely A [2022]. Understanding toxicity associated with boron nitride nanotubes: Review of toxicity studies, exposure assessment at manufacturing facilities, and read-across. JMR 37(24): 4620–4638, https://doi.org/10.1557/s43578-022-00796-8.

Xin X, Barger M, Roach A, Bowers L, Stefaniak A, Kodali V, Glassford E, Dunn KL, Dunn KH, Wolfarth M, Friend S, Leonard S, Kashon M, Porter D, Erdely A, Roberts R [2020]. Toxicity evaluation following pulmonary exposure to an as-manufactured dispersed boron nitride nanotube (BNNT) material in vivo. NanoImpact 19, https://doi.org/10.1016/j.impact.2020.100235.