A newly developed air filtering technique that uses ingredients commonly found in green tea can deactivate germs that find refuge inside air filters, the Ministry of Science and Technology said in an official statement. A research team led by Prof Suryasarathi Bose and Prof Kaushik Chatterjee at Indian Institute of Science (IISc), Bangalore, has developed a germ-destroying air filter that can inactivate germs using ingredients like polyphenols and polycationic polymers commonly found in green tea.