Small world, big challenges
By John Williamson
Nanotechnology is a major new force in the manufacture of products as diverse as car bumpers and drug-delivery micromachines. With its increasingly widespread applications, however, nanotechnology has drawn growing attention to occupational health and safety issues focusing on particles so small that there are few clear-cut guidelines on how to work with them in complete safety. The search for answers is evident in the call for input requested by John Howard, M.D., director of the National Institute for Occupational Safety and Health (NIOSH), Centers for Disease Control and Prevention. In Approaches to Safe Nanotechnology-An Information Exchange with NIOSH (www.cdc.gov/niosh/topics/nanotech), Howard writes that the document’s purpose is to raise awareness of potential safety and health concerns regarding exposure to nanomaterials as well as to encourage the research needed to better understand the potential risks posed by nanotechnology.
The greatest likelihood of exposure is during the manufacture of nanoparticles or nano-enabled products, reports Dr. Clayton Teague, director of the National Nanotechnology Coordination Office in Arlington, Va. (www.nano.gov/html/about/nnco.html). “It is widely known that inhalation of fine particles in conventional industrial operations should be avoided,” he says. “Govern-ment agencies such as NIOSH and the Occupational Safety and Health Administration (OSHA) provide guidance covering areas such as ventilation systems, personal protective equipment use, and laboratory practices. The principles’ guiding efforts to limit exposure should be very similar to those used for other fine particles.”
Dr. Vladimir Murashov, special assistant to the director of NIOSH, says, “To ensure appropriate steps are taken to minimize exposure, a risk management program should be implemented. Elements of such a program should include training workers in the proper handling of nanomaterials, criteria and procedures for installing engineering controls at process locations where exposure might occur, and developing procedures describing personal protective equipment and when it should be worn.”
“Data are lacking on airborne particles smaller than 100 nanometers,” comments Dr. Andrew Maynard, science advisor to the Woodrow Wilson Institute’s Project on Emerging Nanotechnologies. “These particles tend to agglomerate at high concentrations, which is good because then we can control them using conventional methods. We still, however, need to know more about how to dispose of captured particles, and the impact of escaped particles in an open environment.”
Because industry conferences and Web resources abound, there is also a growing need for “information literacy,” a term used by NIOSH’s Dr. Mark Hoover. “People need the skills to seek, find, and effectively use unbiased information,” he says. “And we need to hone in on specific questions for specific materials, rather than [on] generalizations.”
Figure 1. An atomic force microscope in the Class 1,000 (ISO Class 6) cleanroom at the NanoFab nanofabrication facility, the commercial arm of CIVEN in Italy. Photo courtesy of CIVEN.
The quest for guidance is international. Switzerland’s Temas AG (www.temas.ch) has updated “Safety and Risks of Nanotechnology: An overview of completed and ongoing activities,” while CIVEN in Italy (www.civen.org) is a new venture with a project coming online in 2006 dealing with risk assessment of nanoparticles (see Fig. 1).
As the search for answers continues, progress is being made, says Dr. Kevin Ausman, executive director for the Center for Biological and Environmental Nanotechnology (CBEN) at Rice University. “Common sense and best practices should apply,” he says. “For example, gloves or double-gloving should be used in handling nanoparticles in solutions. For airborne particles, studies indicate that high-quality filtration systems do the job, though research should continue.”
Signs of progress
CBEN has teamed with the International Council on Nanotechnology (ICON) to establish an environmental, health and safety database (http://icon.rice.edu
esearch.cfm) as a first effort to organize the massive amounts of information on the impacts of nanoparticles.
Regarding practical applications, Luna Innovations (www.lunainnovations.com) has developed a five-point strategy called NanoSAFE, designed to minimize exposure to workers (see Fig. 2). “The five-point approach is the roadmap to worker protection [with] systems in place to address concerns,” says Matt Hull, a Luna Innovations research scientist.
The Luna nanoWorks division is a pilot-scale facility moving nanotechnology into commercial products. It exemplifies how scientific practices address health issues. Dr. Robert Lenk, CEO of the division, reports that work with Virginia Tech validated an air-handling and filtration system for its efficacy in protecting workers from aerosols in the 2.5-micron to 3-nanometer size range. “We customized existing technology by using the Luna five-point approach to achieve verifiable process improvements without drastic changes in equipment design,” he explains. “Air in the breathing zone showed no increase in particles, whereas particles were visible in the hood zone.”
As nanotechnology moves further into production processes, it’s likely there will be further studies on, and improvements to, worker safety. The good news for operators of cleanrooms is that information on improving already sound, good manufacturing practices continues to develop.