Flame retardants in electrical and electronic industry are growing strongly but pressures are increasing to replace halogen containing additives to halogen free additives. Electrical and electronic (E&E) applications - including housings, wire and cable, and internals such as connectors, are the largest market for flame retardants in plastics globally. Flame retardants are growing well in the E&E markets because of the inherent robust growth of these sectors. As per Specialchem, the need for fire resistance is increasing due to electronics miniaturization and higher temperatures in both processing and use. As electronic parts become smaller and thinner, flame retardants must withstand higher processing temperatures and have minimal affect on the material's flow properties. A flame retardants' affect on electrical properties, measured by the comparative tracking index (CTI), is also important. Formulating with flame retardants is a balancing act between these technical requirements, fire safety regulations, and environmental concerns about flame retardant additives/chemicals.
Fire Safety Regulations
UL standards of V-0, V-1 or V-2 for fire safety are used internationally. These requirements of flame retarancy are decided & regulated by the International Electrotechnical Commission (IEC) in cooperation with the European Committee for Electrotechnical Standardization (CENELEC), with standards defined by application:
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EN/EC 60695 describes tests used to measure flame retardancy, including glow-wire flammability index (GWIF), glow-wire ignition temperature (GWIT), and glow-wire tests for finished materials. Currently the finished materials test for household appliances requires that any flame from the material should extinguish within 2 seconds during application of the glow-wire. This replaced the less-stringent 30 second requirement and could change to 5 seconds sometime in the next 5 years, following round-robin testing. CENELEC's proposal for an external-source test (IEC 62441 defining a "candle accessible area") for television sets was rejected, although fire safety requirements for TVs in Europe should be similar to those in the U.S. , notes an industry source.
Environmental and human health and safety concerns about flame retardant chemicals are an important discussion topic in Europe, and several EU environmental safety directives affect flame retardants. Under REACH (registration, evaluation and authorization of chemicals), flame retardant chemicals have been pre-registered and will undergo risk assessments. Although the environmental safety of Brominated flame retardant chemicals continues to be discussed regularly, the final risk assessment results for Deca BDE and TBBPA, completed under the EU Existing Substances Regulations, were published in the European Commission's Official Journal in May and June 2008. This report concluded that Deca BDE poses no significant risks to the environment or human health which would justify risk reduction measures. For TBBPA (used mainly in printed circuit boards), no health risks were found, The Voluntary Emissions Control Action Programme created by Brominated chemicals manufacturers meets REACH obligations for engaging downstream users in chemical management.
The EU's RoHS (Restriction of the use of certain hazardous substances in electrical and electronic equipment) Directive bans polybrominated biphenyl (PBB) and polybrominated diphenylether (BDE) flame retardant use in E&E. Octa- and penta-BDE have been banned from the EU since August 2004, and are no longer produced globally. The widely-used Deca-BDE was exempted from the RoHS ban in October 2005, based on the results of an EU risk assessment and VECAP's creation in 2004 to control emissions during handling and use of Brominated FRs. Presently, the European Commission's Environment Directorate-General (DG) is discussing revisions to RoHS.
The RoHS directive also restricts lead, driving a change to lead-free solder, which has higher soldering temperatures, and subsequent use of higher-temperature polymers such as high-performance polyamides (HPPA) in electrical connectors and components. Flame retardant systems must withstand these higher temperatures without blistering. The EU's Directive on Waste Electrical and Electronic Equipment (WEEE) requires separation of EE from unsorted waste and then recycling, re-use, and energy-recovery. WEEE also requires separate treatment of plastics containing Brominated flame retardants (BFR), although The Bromine Science and Environmental Forum (BSEF) says studies indicate separate treatment of BFR is not necessary because BFR are compatible with integrated waste management systems. WEEE is currently being reviewed, and proposed revisions might be presented by early 2009. The RoHS and WEEE directives, as well as non-governmental organizations (NGOs), have applied increasing pressure on European industry to change from halogenated flame retardants to halogen-free solutions. While some users are reluctant to change, because the halogen-free solutions may have higher cost and require use of different polymers , halogen-free proponents say that the global industry is moving to halogen-free alternatives and that this trend will continue.
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