David M. Berube, Eileen M. Searson, Timothy S. Morton, and Christopher L. Cummings
The Project on Emerging Nanotechnologies (PEN) product database began in 2005. The PEN Consumer Products Inventory (CPI) has been frequently cited in scholarly and popular articles as well as reports from government and industry. The CPI has been used to establish a baseline or benchmark on the pervasiveness of products produced by nanotechnology and/or incorporating nanoparticles. In this article, a team of researchers examine and validate a sample from the CPI involving four prominent categories of nanoparticles (carbon, gold, silver, and iron). The authors conclude that the CPI has substantive deficiencies that call the validity of claims associated with the CPI into question. Individuals and organizations citing the CPI should be wary of over-claiming the reliability and validity of the presence of nanotechnology in consumer products.