The hospitalization of six Germans after they used a product called Magic Nano has renewed calls for better research into the toxicity of nanoparticles and possibly new laws or regulations governing their manufacture and use.

Since March 27, after a German discount store began offering an aerosolized form of the product, which is a protective sealant for glass and ceramics, 79 people who used the spray have reported breathing problems and coughing. The six who were hospitalized for pulmonary edema have now been released, and typically the symptoms go away in about a day. The number of new cases dropped after the product was pulled from the market two days after its introduction.

Previously, the product had been sold in a pump spray container, and during four years no problems with it were reported, according to Jurgen Kundke, a spokesperson for Germany’s Federal Institute for Risk Assessment. The aerosol form creates a much finer mist of droplets than the pump, possibly allowing the droplets to stay in the air longer or to penetrate further into the lungs, says Kundke.

“We have seen this effect in other sprays with no nanoparticles, so it’s a question of the aerosol and not especially of the nanoparticles,” Kundke says. Although the product is labeled “nano,” Kundke says it might not contain nanotechnology. “The recipes are still secret, he says. “We don’t even know if there was nano in the product.”

Whether or not this version of the Magic Nano product actually contained nanoparticles, however, the incidence is reigniting the debate over the safety of nanomaterials. According to the Woodrow Wilson International Center for Scholars in Washington, DC, more than 200 “nano” products exist. And the distinct properties of nanoparticles – including their potential to penetrated barriers in the body that would otherwise exclude particles – have many concerned about their possible toxicity. Preliminary studies have shown that some types of nanoparticles could cause lung damage in rats, but these studies have not shown similar effects of such particles on humans.

While acknowledging that the cause of the health problems associated with the German product is uncertain, organizations such as The Nanoethics Group, an nonpartisan research organization based in Santa Barbara, CA, say the incident should be a “wake-up call” that the potential risks of nanotechnology are real and deserve more attention by both government and industry. “Historically, it takes something catastrophic, such as widespread injury from asbestos, for real action to be taken. This time, hopefully, we will be smarter than that and not wait for the other shoe to drop,” says the group’s research director, Patrick Lin.

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.