Following the circuit board industry regulations IEC61249-2-21 provides halogen-free circuit boards manufactured chlorine and bromine limited value after the well-known electrical and electronic manufacturing companies have released DELL APPLE and requirements for its products of chlorine and bromine should reach a certain limit. This will become an industry trend, that business will gradually use halogen-free flame retardants.
    
Halogen includes fluorine (F), chlorine (Cl), bromine (Br), iodine (I), astatine (At) five kinds, including astatine (At) is a synthetic radioactive substances, often said halogen is currently testing generally refers to former of four.

International Standard Halogen requirement limits