the halogens or halogen elements are a series of nonmetal elements from group 17 iupac style (formerly: vii, viia) of the periodic table, comprising of fluorine (f), chlorine (cl), bromine (br), iodine (i), and astatine (at). since astatine (at) is a radioactive element, halogens usually refer to fluorine (f), chlorine (cl), bromine (br) and iodine (i). halogens are often present in the form of organic compounds in the product, especially in the polymer materials.
generally speaking,polymeric materials with halogen elements (fluorine, chlorine, bromine, iodine) tend to have higher burning points (about 300℃) than common polymer materials. halogenated gases (fluorine, chlorine, bromine, iodine) will be emitted and absorb oxygen immediately during the burning process so as to put out fire. halogenated polymer materials will release corrosive and toxic gases if ignited in a fire. the corrosive element (i. e. chlorine) of these gases poses a risk to immune and endocrine systems, brings harm to reproduction and development, or even causes cancers. for your information, most halides are environment disruptors. furthermore, corrosive gases (hydrogen halide) resulting from the combination of halogenated gases (released during the burning of halogenated elements) and water vapour may corrode equipment and buildings.
uses of halogens
the main substances used as flame retardants are as follows: polybrominated biphenyl (pbb), polybrominated diphenyl ethers(pbdes), tetrabromobisphenol a (tbbp-a), polychlorinated biphenyl (pcb), polychlorinated terphenyl (pct), polychlorinated naphthalenes (pcns), hexabromocyclododecane (hbcdd), tribromophenol (tbp), short-chain chlorinated paraffins (sccp).
products of high concern: circuit boards, computers, fuel cells, television sets, typewriters, etc.
the ozone depleting substances: chloro flouro carbon (cfcs), hydrochlorofluorocarbon (hcfcs), hydrochlorofluorocarbons (hfcs), etc.
products of high concern: refrigerants, insulation materials, etc.
regulations for halogens restriction:
eu rohs 2.0 (directive 2011/65/eu) | brominated flame retardants |
montreal protocol on substances that deplete the ozone layer(global) | cfcs (5), halon (3) |
stockholm convention, eu pops regulation | ocps, hcb, pcbs, pcdds, pcdfs,pbdes |
iec non-halogenated requirements (iec61249-2-21) | cl≤900ppm, br≤900ppm, cl br≤1,500ppm |
c&k testing can provide professional testing for halogens as per standards of different countries and regions. besides, we can render you one-stop solutions integrating consulting, testing and certification. please feel free to contact if any question. staffed by experienced specialists, c&k testing can assure you of the quality and safety of your products by our professional testing services as per different standards.
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