The Economist on Nano Safety

Posted on December 5, 2007 by Patrick T. Lewis

The November 22, 2007 issue of The Economist contains a story on nanotechnology safety entitled "A little risky business."   The article focuses on Andrew Maynard's presentation before the House Science Commitee in October, an event we covered here, and also covers the ongoing debate over the use of silver nanoparticles as an antimicrobial agent in consumer products. 

All in all, the Economist article I think provides a useful synopsis of the current dilemma surrounding nanotechnology safety.   Its safety discussion begins with a discussion of the distinction between naturally occurring nanoparticles and engineered nanoparticles:

All that sounds alarming, but assessing the risks calls for perspective. Humans are already surrounded by nanoparticles of one sort or another. Much of the food people eat is made of naturally occurring nanoscaled components. Each person breathes in at least 10m nanoparticles a minute. Most of them do no harm.

That said, I am a little disappointed that the article did not sufficiently emphasize the inconclusive nature of the animal studies on nano safety.  The article only alludes to studies that show the potential for toxicity:

[s]tudies show there is the potential for such materials to cause pulmonary inflammation; to move from the lungs to other organs; to have surprising biological toxicity; to move from within the skin to the lymphatic system; and possibly to move across cell membranes.

However, we also know that there are a number of studies that suggest that nanomaterials may not have significant toxic effects -- see, e.g., Nano Law Report's coverage of the buckyball study and the study looking at SWNTs in fruit flies. 

With all of that said, the article's bottom line strikes me as reasonable -- that we need to do a better job learning what the risks of nanomaterials are so that we can responsibly regulate their use and manufacture and not lose the "baby with the bathwater" in the process.
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Geckos use nanotechnology?

Posted on December 22, 2006 by Patrick T. Lewis

A gecko's amazing ability to cling to walls and ceilings is an ability that scientists have studied for decades.  Recent research suggests that the gecko's abilities owe to 200 nm adhesive hairs on the gecko's feet.  While the traditional definition of nanotechnology requires that the material be smaller than 100 nm, we are willing to make an exception for the gecko. 

Nanowerk reports that researchers at the Max-Planck Institute for Metals Research in Germany have leveraged this research to create new adhesive materials:

Copying the biological adhesive mechanism, the Max-Planck scientists used the insights gained from their years of research to develop a material with a biomimetic structure that exhibits excellent adhesive qualities. The special surface structure of the material allows it to stick to smooth walls without any adhesives. Potential applications range from reusable adhesive tape to shoe soles for climbing robots and are therefore of considerable relevance to technology.

The Nanowerk article is unclear as ot whether the new material actually employs nanoscale fibers.  This actually raises an intriguing question about nanotechnology regulation;  if we accept that 100 nm is the largest "nanomaterial," then presumably gecko feet and other "almost" nanoscale materials are not subject to the regulation.  However, I am not sure whether the alleged human health hazards associated with nanomaterials sharply diminish once the particle exceeds 100 nm in length along any one axis.   

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UPDATE: First EPA Regulation of Nanotechnology?

Posted on November 28, 2006 by Michael E. Heintz
Since first being reported in the Washington Post, and relayed here, more information concerning EPA's proposed regulation of nanosilver under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) has been uncovered.

As initially reported, the EPA's Office of Pollution Prevention reversed its course from earlier statements, and ultimately decided to regulate nanosilver under the FIFRA.  EPA reasoned that because manufacturers were producing products containing nanosilver as a method of killing bacteria, such uses were properly the province of the FIFRA as a pesticide.  Nanosilver is found in several products available today, including food containers, shoes, air fresheners, and bandages.  The concern is that the silver may pose a threat to aquatic systems as a bio-accumulative toxin.

Upon further research into EPA's announcement, it has been determined that EPA plans to issue a Federal Register notice that will explain the requirements for using nanosilver as an anti-bacterial agent.  Greenwire is reporting that the rule will be issued "within the next few months."  It is expected that those falling under this new rule will need to show that the nanosilver additive will not pose an environmental risk when placed into commerce.  However, as reported in the November 23, 2006 Washington Post article, EPA states that to be subject to FIFRA regulation, there has to be a claim that the product will "kill pests" in order for it to be a pesticide.  Consequently, products containing nanosilver may not be subject to FIFRA regulation absent a claim that the product kills bacteria, viruses, or the like.

The most important piece of information to come out of this subsequent research is the knowledge that EPA will indeed begin regulating nanomaterials, and plans to do so soon.  Silver is already regulated under the FIFRA in several products as a pesticide, so for EPA to regulate forms of nanosilver is potentially a new step.  The Federal Register notice should provide additional details as to how nanosilver will be regulated under the FIFRA and the procedures EPA will use in determining which uses are subject to regulation and which are not.  It is important to note that nanomaterials are not currently regulated, however it appears as though regulation is now imminent, starting with nanosilver in anti-bacterial uses.
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