Halogen-free PCB -- halogen (halogen) is a group VII a non-gold Duzhi element in Bai, including five elements: fluorine, chlorine, bromine, iodine and astatine. Astatine is a radioactive element, and the halogen is usually referred to as fluorine, chlorine, bromine and iodine. Halogen-free PCB is environmental protection PCB does not contain the above elements.
