Perhaps you can relate to this situation: Just as our client’s sales force was poised to ship a hot new product to a dozen market countries, one of the process chemists happened to mention to the environmental manager that the product contained a “nano” component. Suddenly these small particles became a very big deal to the environmental manager, who needed to determine the relevant regulatory restrictions on a tight schedule.
Although the use of nanomaterials dates back centuries, commercial use has increased dramatically over the last decade as manufacturers have used their unique properties to create competitive advantage. In response to this increased use, environmental managers now must navigate an ever-evolving suite of regulations and health and safety precautions for those employees working with nanomaterials.
Nanomaterials can offer increased strength, conductivity, or reactivity, but particle size can also affect certain physicochemical properties, and even the toxicological effects of the substance. These may include:
- Decreasing the size of a particle increases the relative proportion of atoms on the surface. Consequently, the dissolution rate and the relative rate of reactivity can increase, for example.
- Each atom on the particle surface has fewer bonds than it would have if it were located in the middle of the particle. As a result, the energy associated with those atoms, known as the “surface free energy” differs from the free energy associated with atoms in the center of the particle. The surface free energy can affect such physical properties as the melting point, equilibrium solubility, and reactivity. The latter explains why nanoscale catalysts can be so effective.
- When the diameter of the particle is of the same magnitude as the wavelength of the electron wave function, so-called “quantum effects” occur. At this point the electrical and optical properties of the particle may change, allowing for carbon nanotubes to conduct electricity, or silver particles to appear blue, for example.
Managing the potential risks of nanomaterials can be a daunting challenge for environmental managers. One of the most difficult issues to solve is that regulators around the world define “nanomaterial” differently, with the size cutoff ranging up to 2000 nanometers (nm) and some definitions including other parameters. An environmental manager concerned with product registration must carefully parse the regulatory definitions and their application to nanomaterials, to determine if their products are regulated differently than bulk materials. Other environment, health and safety (EHS) risks associated with nano-scale materials include:
- Evolving product registration requirements;
- Appropriate health and safety precautions for workers;
- Waste management;
- Perceptions and misperceptions by customers; and
- Other life cycle concerns.
The scenario described at the beginning of this blog ended with a twist. Although the raw material supplier characterized their product as a nanomaterial, perhaps for the “cool factor” associated with the name, it did not actually meet the regulatory definition of a nanomaterial in any of the market countries. No special registration, classification, or labelling provisions applied to the material, and our client’s product could be shipped without delay.
Kate Sellers will continue the discussion about managing nano-scale materials during NAEM’s upcoming webinar, “Understanding the EHS Opportunities and Challenges of Nanotechnology” on August 16.