University of Pittsburgh researchers have developed a natural, nontoxic method for biodegrading carbon nanotubes, a finding that could help diminish the environmental and health concerns that mar the otherwise bright prospects of the superstrong materials commonly used in products from electronics to plastics. The team found that carbon nanotubes deteriorate when exposed to the natural enzyme horseradish peroxidase (HRP). These results open the door to further development of safe and natural methods of cleaning up carbon nanotube spills in the environment and in the industrial or laboratory setting. The team's work focused on nanotubes in their raw form as a fine, graphite-like powder, a form that has caused severe lung inflammation in lab tests. To break down the nanotubes, the team exposed them to a solution of HRP and a low concentration of hydrogen peroxide at 4 °C (39 °F) for 12 weeks. Once fully developed, this method could be administered as easily as chemical clean-ups in today's labs, the researchers said.