A statement from New York City-based Environmental Defense recommends spending more on testing nanomaterials before they get to market, plugging holes in regulations that leave them uncovered, and avoiding the use of nanoparticles in "dispersive" applications, such as aerosols, until more is known about their effects.

Incidents with products such as the German one could help to direct research efforts, says Kevin Ausman, executive director at the Center for Biological and Environmental Nanotechnology (CBEN) at Rice University in Houston, TX. In this case, the difference in reactions to the pump and aerosol forms of the product suggest that research is needed on how the size of droplets or the interactions between nanoparticles and a propellant could affect toxicity. CBEN also advocates studying carefully purified forms of nanoparticles to learn about their general properties, with the goal of being able to predict their toxicity.

Alan Gotcher, CEO of Altair Nanotechnologies of Reno, NV, who has testified before Congress about the need for more funding for nanotoxicity research, says the manufacturers of Magic Nano should disclose the ingredients of the product. "We need to understand the product, understand if there is nanomaterial in it, and, if so, what it is and characterize it. The companies that sold the product and manufactured it have an obligation to follow up on this problem, disclose their data, and be candid." If manufacturers don't act responsibly, he adds, it could require government intervention in the form of new laws and regulations.

Coincidentally, the Magic Nano incident happened at the same time that a symposium on nanotechnology sponsored by the Federal Institute of Risk Assessment was discussing the lack of research on the toxicity of nanoparticles. "When it comes to sprays, we don't know anything at the moment, and we don't even have models to test the toxicology of nanoparticles," says Kundke.