Controlling Exposures to Workers Who Make or Use Nanomaterials

Background

It is difficult to estimate how many workers are involved in this field. By one estimate, there are 400,000 workers worldwide in the field of nanotechnology, with an estimated 150,000 of those in the United States [Roco et al. 2010]. The National Science Foundation has estimated that approximately 6 million workers will be employed in nanotechnology industries worldwide by 2020.

Occupational health risks associated with manufacturing and using nanomaterials are not yet clearly understood.  However, initial toxicological data indicate that there is reason for caution. NIOSH is committed to promoting the responsible development and advancement of nanotechnology through its research and communication efforts to protect workers. NIOSH has taken a leading role in conducting research and making recommendations for nanotechnology safety in work settings.  See the nanotechnology topic page for a list of documents and resources.

Recently, NIOSH has released a document titled, Current Strategies for Engineering Controls in Nanomaterial Production and Downstream Handling Processes, which provides information on how to control exposures for many of the most common processes seen in facilities that use or produce nanomaterials or nano-enabled products.

How are workers exposed?

The greatest exposures to raw nanomaterials are likely to occur in the workplace during production, handling, secondary processing, and packaging. In a review of exposure assessments conducted at nanotechnology plants and laboratories, Dr. Derk Brouwer determined that activities which resulted in exposures included harvesting (e.g., scraping materials out of reactors), bagging, packaging, and reactor cleaning [Brouwer 2010]. Downstream activities that may release nanomaterials include bag dumping, manual transfer between processes, mixing or compounding, powder sifting, and machining of parts that contain nanomaterials.  Similar to controlling hazards in traditional macro-scale manufacturing, engineering controls are recommended to reduce exposures to nanomaterials.  The identification and adoption of effective control technologies is an important first step in reducing the risk associated with worker exposure to engineered nanoparticles.  Properly designing and evaluating the effectiveness of these controls is a key component in a comprehensive health and safety program.

Strategies for Protecting Workers

NIOSH’s new document discusses approaches and strategies to protect workers from potentially harmful exposures during nanomaterial manufacturing, use, and handling processes. Its purpose is to provide the best available current knowledge of how workers may be exposed and provide guidance on exposure control and evaluation. It is intended to be used as a reference by plant managers and owners who are responsible for making decisions regarding capital allocations, as well as health and safety professionals, engineers, and industrial hygienists who are specifically charged with protecting worker health in this new and growing field. Because little has been published on exposure controls in the production and use of nanomaterials, this document focuses on applications that have relevance to the field of nanotechnology and on engineering control technologies currently used, and known to be effective, in other industries.

Assessing how well the exposure control works is also essential for verifying that the exposure goals of the facility have been successfully met. This document covers a range of control evaluation tools including airflow visualization and measurement and containment test methods, such as tracer gas testing. Additional methods, such as video exposure monitoring, also provide information on critical task-based exposures and helps identify high-exposure activities and help provide the basis for interventions.

Help Wanted: How You Can Get Involved

Producers and users of engineered nanomaterials are invited and encouraged to partner with NIOSH. Companies that have installed exposure controls, such as local exhaust ventilation, or are interested in assessing and reducing worker exposures can work with NIOSH engineers to develop and evaluate exposure mitigation options. Partnering with NIOSH not only benefits your company by providing an assessment of process emissions and recommending effective exposure control approaches  but also expands the knowledge base that benefits the industry as a whole.  Please feel free to contact us through the comment section below. Thank for your interest in protecting workers!

Jennifer L. Topmiller, MS

Kevin H. Dunn, Sc.D., CIH

Ms. Topmiller is the Team leader of the Control Technology Team and Dr. Dunn is a research mechanical engineer in the Engineering and Physical Hazards Branch in the NIOSH Division of Applied Research and Technology.

References

Brouwer D [2010]. Exposure to manufactured nanoparticles in different workplaces. Toxicology 269(2):120-127.

Roco MC, Mirkin CA, Hersam MC [2010]. Nanotechnology research directions for societal needs in 2020: Retrospective and outlook. Arlington, VA: National Science Foundation.

WWICS [2011]. The Project on Emerging Nanotechnologies: Consumer Product Inventory. [http://www.nanotechproject.org/inventories/consumer/updates/]. Date accessed: October 18.