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PubMed | German Federal Institute for Risk Assessment, SouthWest NanoTechnologies (SWeNT), Lockheed Martin, Brown University and 15 more.
Type: Journal Article | Journal: ACS nano | Year: 2015

For nanotechnology to meet its potential as a game-changing and sustainable technology, it is important to ensure that the engineered nanomaterials and nanoenabled products that gain entry to the marketplace are safe and effective. Tools and methods are needed for regulatory purposes to allow rapid material categorization according to human health and environmental risk potential, so that materials of high concern can be targeted for additional scrutiny, while material categories that pose the least risk can receive expedited review. Using carbon nanotubes as an example, we discuss how data from alternative testing strategies can be used to facilitate engineered nanomaterial categorization according to risk potential and how such an approach could facilitate regulatory decision-making in the future.

Reed K.,Cerion NRx LLC | Cormack A.,Alfred University | Kulkarni A.,CSIRO | Mayton M.,Spinnaker Cross Inc. | And 3 more authors.
Environmental Science: Nano | Year: 2014

Nanoceria is an exceptionally versatile, commercially valuable catalytic material whose properties vary dramatically from that of the bulk material. Nanoceria's redox properties can be tuned by choice of method of preparation, particle size, nature and level of dopant, particle shape and surface chemistry. The two oxidation states of the cerium element in the lattice make possible the formation of oxygen vacancies which are essential to the high reactivity of the material, its oxygen buffering capability and thus its ability to act as a catalyst for both oxidation and reduction reactions. Ceria has important commercial utility in the areas of chemical mechanical polishing and planarization, catalytic converters and diesel oxidation catalysts, intermediate temperature solid oxide fuel cells and sensors. Its potential future uses include chemical looping combustion, photolytic and thermolytic water splitting for hydrogen production and as a therapeutic agent for the treatment of certain human diseases. We have seen that the method of synthesis, particle size, stabilizing corona, and purity dictate where it is used commercially. Finally, in regards to the prescient words of Dr. Feynman, we note that while there is indeed "plenty of room at the bottom", there quite possibly exists an optimal nanoceria size of between 2-3 nm that provides maximal reactivity and thermodynamic stability. © 2014 the Partner Organisations.

Holden P.A.,University of California at Santa Barbara | Klaessig F.,Pennsylvania Bio Nano Systems | Klaessig F.,University of California at Santa Barbara | Turco R.F.,Purdue University | And 8 more authors.
Environmental Science and Technology | Year: 2014

Manufactured nanomaterials (MNMs) are increasingly produced and used in consumer goods, yet our knowledge regarding their environmental risks is limited. Environmental risks are assessed by characterizing exposure levels and biological receptor effects. As MNMs have rarely been quantified in environmental samples, our understanding of exposure level is limited. Absent direct measurements, environmental MNM concentrations are estimated from exposure modeling. Hazard, the potential for effects on biological receptors, is measured in the laboratory using a range of administered MNM concentrations. Yet concerns have been raised regarding the "relevancy" of hazard assessments, particularly when the administered MNM concentrations exceed those predicted to occur in the environment. What MNM concentrations are administered in hazard assessments and which are "environmentally relevant"? This review regards MNM concentrations in hazard assessments, from over 600 peer-reviewed articles published between 2008 and 2013. Some administered MNM concentrations overlap with, but many diverge from, predicted environmental concentrations. Other uncertainties influence the environmental relevance of current hazard assessments and exposure models, including test conditions, bioavailable concentrations, mode of action, MNM production volumes, and model validation. Therefore, it may be premature for MNM risk research to sanction information on the basis of concentration "environmental relevance". © 2014 American Chemical Society.

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