ETAG (European Technology Assessment Group), The Role of Nanotechnology in Chemical Substitution, STOA (Scientific Technological Options Assessment): ETAG, http://www.itas.fzk.de/eng/etag/project.htm, October 2006.
There are quite a few caveats to the report. For example, "[o]nly substances which are already known as toxic and dangerous to humans and the environment are considered" (p. v) and "...everything is considered as nanotechnology (NT) which is claimed by proponents to be nanotechnology" (p. v). Findings are placed in seven categories; coatings, flame retardants, flexibilizers, catalysts, and NT used to substitute or reduce solvents, NT used for remediation, and other examples. The report concluded "NT can not contribute in an exceptional manner to a large increase of substitution of hazardous substances (p. viii).
One of the primary problems with the concept of pollution prevention/chemical substitution is noted early in the report. "[A]pplications mostly exist only as ideas and concepts and have not even been proven in the laboratory" (p. 1). On p. 4, ETAG, like many others, argues a contagion effect. "[T]he outcome of the debate over NT can significantly influence the development of the technologies concerned" (p. 4) . In addition it relates the debate over NT "like the debate on nuclear energy, stem cell research or genetic engineering" (p. 4). Both of these assumptions are not necessarily true nor does the report spend any more time explicating them.
Some of the best evidence of substitution entails bifouling (nanostructuring of surfaces), alternatives to brominated flame retardants, alternatives to lead batteries, reducing the use of solvents, and reducing the used of insecticides by improving performance through the use of sensors. On p. 10, there is a hit list of substances from heavy metals to toxic organic pollutants which should be considered as worthy of substitutability research.
On pp. 15-16, there is a well worth reading review of self-cleaning surface technologies with specific examples. The review of silver particle-based coatings was rather superficials (p. 17) though the review of paints, sealants, and corrosion protection coatings (pp. 17-18) though brief is notable. The case on flame retardants (p. 20) is also notable.
The issue here is the environmental footprint of nanotechnology, read as nanoparticles at this time. While there may be a lot of promise, there isn't a lot of real experience. Once the remediation literature is set aside, there is very little to work from which makes risk studies on nanotechnology so problematic.
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