Nanotechnology has expanded tremendously over the last 20 years, transitioning from research and development (R&D) laboratory experiments to many applied technologies. The technology incorporates microscopic-sized particles measuring 1 to 100 nanometers (a human hair is 75,000 nanometers in diameter). Scientists have become incredibly adept at producing nanoparticles by either mechanically crushing the source material or building up tiny structures through chemical processing.

“Nanotechnology is essentially everywhere now, from its ability to provide life-saving treatments in medicine to improving strength and resilience in polymers, coatings, dispersions or composites in manufacturing,” said Sonya Luisoni, Senior Risk Service Manager at Safety National. “However, according to the National Institute for Occupational Safety and Health (NIOSH), there is still a challenge in comprehending how the physiochemical characteristics of these particles, like shape, charge, chemical properties and solubility, can influence the biological systems of employees.”

Exposure Unknowns

Despite decades of development, the Centers for Disease Control and Prevention (CDC), the Occupational Safety and Health Administration (OSHA) and NIOSH are still trying to understand nanotechnology’s impact on employee health. Nanomaterials have the greatest potential to enter the body through the respiratory system if airborne, but they can also enter through the skin or be ingested. Only a few occupational exposure limits exist for specific nanomaterials like carbon, titanium dioxide and silver.

Fortunately, the NIOSH Nanotechnology Research Center (NTRC), established in 2004, leads the federal government’s health and safety initiative for nanotechnology research. The Nanotechnology Guidance & Publications webpage presents up-to-date research and workplace design solutions to protect workers handling nanomaterials. NIOSH also offers free assessments of workplace processes, materials and control technologies for research laboratories, producers and manufacturers working with engineered nanomaterials.

Assessing Exposure

When considering potential exposure to nanoparticles from a practical perspective, it is critical to first understand what form they are in when handled. Does the process involve feedstock nanoparticles, or are the nanoparticles already encapsulated within a medium combined with other products? Examples of feedstock include laboratory generation, R&D facility research and early stages of product formulation. Exposure risks are higher if feedstock nanoparticles are in powder form or within a highly-agitated liquid. NIOSH’s “Protecting Workers during the Handling of Nanomaterials” guidance document provides detailed guidance on exposure control when handling feedstock nanomaterials.

When nanoparticles are already encapsulated within products, exposure may be notably less. Consider products such as nanocomposites, surface-coated materials and materials comprised of nanostructures (e.g., integrated circuits) where nanoparticles have already been integrated into the production medium. Keep in mind exposure risks increase if nano-enabled products are cut, sanded, ground or sprayed and may necessitate well-designed exhaust ventilation systems with high-efficiency particulate air (HEPA) filters. Maintenance personnel may be exposed to nanoparticles when maintaining production equipment (i.e., cleaning and disposal of materials from dust collection systems). If an in-situ ventilation system is not feasible, then specialized HEPA vacuum systems and respiratory protection should be considered.