Nanotechnology is a relatively new technology with the potential for significant impact on society. Nanoparticles have been around for hundreds of years, but the invention of microscopes that can see atomic-sized particles made it possible for scientists to develop a wide variety of uses.
Nanoparticles are extremely small. They are generally from 1 to 100 nanometers, that is, one-billionth of a meter. A two-nanometer-size particle is more than 10 billion times smaller than a red blood cell. For perspective, a human hair is 20,000 nanometers.
When materials are reduced to the nanoparticle level, they may have different properties, such as increased strength or making coatings more slippery. This change in properties makes it possible to deliver medication to specific areas, create a fabric that is stronger or that doesn’t wrinkle, or create medical bandages that fight bacteria, among other applications.
Nanoparticles can enhance consumer products, advance medical treatments, improve building components, and help in the cleanup of contaminated sites, for example. However, one downside is that the small size of nanoparticles allows them to enter the body through the skin, enter the bloodstream and cross the blood-brain barrier, pass through lung tissue, affect cells and accumulate in the air or soil, along with other potentially harmful effects. This possibility combined with the potential of the nanoparticles having different characteristics than the macroparticles raises some concerns about safety.
Toxicity and cancer
There are concerns that nanoparticles could lead to cancer. Toxicity depends on the type of nanoparticle and the type of exposure. Nanoparticles embedded in final products such as fabric may cause no problems, while the inhalation of powder could lead to complications similar to those found with asbestos.
Studies of titanium dioxide have shown that low toxicity particles of fine and ultrafine (nanoscale) sizes have exhibited pulmonary responses in exposed rats, including inflammation and lung tumors. Exposure to carbon nanotubes and nanofibers has shown similar results. Although there is no hard evidence that exposure to nanoparticles can eventually lead to cancer, the National Institute of Occupational Safety and Health (NIOSH) has developed guidelines for workplaces to follow if employees are exposed to nanoparticles and posters that can be displayed in the workplace as well.
Dry powders present the most potential for exposure, either through the skin or through inhalation. Likewise, nanomaterials suspended in liquids have the potential for inhalation when in spray form.
Various controls are recommended for various exposures. Fume hoods, ventilated bagging stations, exhaust vents, ventilated spray booths, downdraft tables and wet cutting or machining are all recommended ways to control exposure.
The use of procedures when handling nanoparticles is recommended, as well as training workers on the risks of exposure and how to handle the materials. The use of personal protective equipment is recommended when other measures can’t guarantee safety. The use of gloves, lab coats or coveralls, safety glasses or face shields, and respiratory protection are all recommended for workers who may be exposed to the particles.
Exposure to asbestos presents a known risk of cancer, although it took several decades of exposure before bans were put in place. The Environmental Protection Agency banned it in 1989, overturned that ban in 1991 and put a new ban in place in 20007. The EU and France banned all forms of asbestos in 1998. The United States is considering allowing some specific uses of asbestos once again, even though new cases of mesothelioma, which is caused by exposure to asbestos, continue to occur.
It’s important to control the exposure of workers to nanomaterials as much as possible. Because of the studies so far, NIOSH has set an acceptable exposure limit of one microgram per cubic meter of elemental carbon as a respirable mass eight-hour time-weighted concentration. The exposure to raw materials is different from exposure to sunscreen and other end products, but nanomaterials may not be completely safe.
A factory worker in 1898 warned of the harmful effects of asbestos, and over subsequent years there were more suspicions linking asbestos to disease and death before countries finally banned it. What if it works the same way for nanoparticles, and not just for workers, but for consumers as well? One inventory lists 1,827 products containing nanomaterials. Items range from sheets to bicycle-cleaning kits to socks to hair dryers to lip balm, among others. With this wide range of products, the unknown aspect of whether nanomaterials do have detrimental effects or whether they might over long-term exposure is significant.
Product liability issues
Substantial product liability issues may arise. One factor, of course, will be which product the consumer was exposed to that caused the ill effects. With asbestos, the product exposure is limited. Nanoparticles could be in almost anything. At the point of illness related to exposure, would the consumer have to prove that it was the lip balm and not the sheets or sunscreen that caused the illness, or would there be reasonable claims against all manufacturers on a proportional basis? The product liability exposure is enormous, and something the industry should look at going forward.
Nanoparticles are in many ways useful and exciting technology, but there are concerns. These concerns must be carefully reviewed and studied so that people, and particularly workers, are protected from possibly serious effects.
Christine G. Barlow, CPCU, is the managing editor of FC&S Online, the authority on insurance coverage interpretation and analysis for the P&C industry. She can be reached at email@example.com.