Nanotechnology is fashionable, but fashion is transient. Is it going away or is it here to stay? We now know that yesterday’s science fiction is already in our lives, you only have to think of cell phones, micro-computers, etc. Nanotechnology involves design, characterization, production, and application of structures, devices, and systems by controlling shape and size as per the nanoscale.
The nanoparticles (NP) can be described as particles having at least one dimension less than 100 nanometers (nm). The nanometer unit is used to denote a measure of the order of billionths of a meter (0.000000001 or 1 x 10^-9). More specifically, a diameter of 30,000 times smaller than the thickness of one hair. The nanoparticles (NP) are new particles yes, but not all of them are new! Some have indeed been issued for a long time even if we do not realize it, they can be of natural origin, since they are present in the environment, for example, through combustion products released during forest fires or volcanoes; they can be caused by human activity, for example, products of combustion and exhaust gas coming from diesel engines; they can be manufactured by man, for example: Carbon black (tires), titanium dioxide, or TiO2 (white paints, toothpaste, sunscreen).
However, the current craze is mainly with the new particles whose production is based on the properties of their smaller size allowing new industrial and commercial opportunities. For example, it is estimated that carbon nanotube offers 100 times the strength of steel.
Included as Examples of Nanoparticles:
- Fullerenes, they are spherical cages containing from 28 to more than 100 carbon atoms
- Carbon nanotubes, they are carbon molecules coiled in a hexagonal network of carbon atoms to form the hollow cylinders with a single wall (SWCNT for Single Walled Carbon Nanotubes) or multi-walled (MWCNT for Multi Walled Carbon Nanotubes) cylinders coaxial with increasing diameters in the same axis
- Quantum dot, they are formed of a colloidal core surrounded by one or more surface coatings
- Nano capsules, Nano spheres, Nano shells, are insoluble organic polymers
- Dendrimer, which are star polymers which contain multiple concentric branches (arborescence)
There are also many other organic nanoparticles (for example, polystyrene and doxorubicin) and inorganic nanoparticles (made of metals such as gold, of various inorganic compounds or alloys such as TiO 2).
Did you know that 573 industries identified within the United States and 51 in Canada use them in processes, manufacturing, research and development, etc.? Many products based on nanotechnology, made here or elsewhere, are already available and used. The development, manufacture and applications of nanoparticles and nanomaterials should diversify and grow over the coming years. They can be found in materials, which allows to manufacture products with new mechanical properties such as increased strength of glass to wear and tear or scratches, greater adherence of tires; in electronics, to develop data storage devices smaller, faster and more energy-efficient; in optics, for microscopes and new instrumentations, for example: Lithography Nano imprint; in consumer products such as sunscreen and anti-wrinkle creams, fibers to improve hockey sticks and golf clubs (durability, lightness, etc.), textiles with anti-stain, and wrinkle resistant properties, stains for wood more wear resistant, and anti-graffiti paints; in biology and medicine for improving design and targeting of drugs, for biomedical analysis to better characterize microorganisms for example Lab-on-a-chip (DNA chip), for better diagnosis by imaging, for the self-assembly of atoms and molecules to make Nano engines, Nano-objects, and Nano-robots for space exploration, oil fields, etc…
Nanoparticles have different properties from those of larger particles of the same product. Generally, if they are smaller, they can be more reactive and can also be toxic. They can have a significant impact on any worker’s health. Being that small, the nanoparticles can easily enter the body and generate effects such as oxidative stress, protein and genetic interactions. Not too many studies can be found on the subject. There are very few in vivo animal studies and human data is almost inexistent. However, available data does cover only a fraction of the information required to conclude definitively on the toxicity or the safety of the product.
Production and usage of nanoparticles can cause different hazards: chemical incompatibilities, fires, explosions, electrical risks, health effects, etc. Development and implementation of a prevention program should cover various aspects like; identification and assessment of the risks specific to nanoparticles used or produced, the assessment of occupational exposure levels, criteria and procedures allowing the installation of engineering controls, information and worker training (hazards, work procedures, equipment use, how to handle nanoparticles, preventive measures and personal protective equipment) evaluation performance and the effectiveness of different exposure control.
If the material is a powder, suspension or inclusion in a matrix, specific known risks such as (toxicity, reactivity, flammability, and explosiveness) must be considered in a prevention program, including the ones from the SDS provider.
Federal and provincial health and safety regulations cover general aspects of the obligations in terms of developing occupational prevention programs and how to control contaminants in the workplace. The Workplace Hazardous Material Information System (WHMIS) is a Canadian system that requires suppliers to label chemical substances and to produce safety data sheets describing the various products, their main physical characteristics, and risks to health, safety and preventive measures put in place. Employers must make them available and train their workers. Several other provincial or federal laws, such as the transport of dangerous goods regulations, may apply to nanoparticles as they apply to other chemicals but no law as far as we know covers specifically nanoparticles.
The hazards during certain activities may appear to be less of a concern because they usually involve workers trained and informed, for example, those working in research and development. However, it’s different when it comes to activities such as bagging, transporting, construction, recovery, cleaning, maintenance, etc. There is little data available on the toxicity of nanoparticles and even less about commercial products and compounds in manufactured goods or from processes using nanotechnology.
To learn more:
Canadian NanoBusiness Alliance
National Institute for Nanotechnology (NINT)
NIOSH. Interim Guidance on Medical Screening of Workers Potentially Exposed to Engineered Nanoparticles http://www.cdc.gov/niosh/docket/archive/docket115.html