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USEPA Risk Assessments for Nanomaterials

Nanotechnology refers broadly to the science of fabricating chemical devices that are 100 nanometers or smaller. By way of illustration, a sheet of paper is approximately 100,000 nanometers thick, or 1,000 times the size of the largest nanomaterial. The United States Environmental Protection Agency and the National Institute of Environmental Health Sciences are working on the development of methods to quickly screen nanomaterials to identify hazards that warrant further scrutiny. Nanoscience and nanotechnology are relatively new, but already nanoparticles made from C60 (Buckminster fullerenes or “buckyballs”) are finding potential applications in consumer products ranging from car lubricants to cosmetics and medicines.

The first phase of the USEPA's National Center for Computational Toxicology’s ToxCast initiative, which includes the use of high-throughput screening assays to profile the biological activity of environmentally relevant chemicals, has been completed. The results of the first-phase analysis will be presented in March.

Recent research conducted in the Netherlands indicates that nanoparticles, when introduced into aquatic environments, may interact with other conventional pollutants and result in increasing their toxicity to plant and animal life. Additional nanoparticle risk assessments are required to take into account not just the toxicity of the nanoparticles themselves, but also the possible interaction with other environmental contaminants. 

Some basic precautionary measures have been suggested by organizations such as the Health and Safety Executive (HSE) of UK, and the National Institute for Occupational Safety and Health (NIOSH). These measures include treating all nanomaterials that may possess unique physical chemical properties as "new chemicals" for regulatory purposes. Current material safety and data information can only be viewed, at best, as a starting point for assessing the risk of a nanomaterial product. An example is carbon, which is practically non-toxic as a raw material; but scientists have already established a toxicity level of oral lethal dose 50 (LD50) of 300 mg/kg for C60 “buckyballs”. This toxicity level is considered moderately toxic.

For more information, please contact John Elliott at (925) 403-6200.