Alternatives generally exist and there is no information about any current production. However, it is reported that many articles in use still contain these chemicals.
Note that following information is extracted from the risk management evaluation document (UNEP-POPS-POPRC.4-15-Add.1).
The phase out of c-OctaBDE is already advanced: production has stopped in the EU, USA and Canada. Voluntary phase out by industry is underway in Japan. In light of the ban and phase out of c-OctaBDE in 2004 in the European Union and an already increasing use of alternatives, the availability of practicable and economically viable substitutes has already been demonstrated in practice (see INF document related to this paper).
Design changes can eliminate the need for flame retardants by using alternative materials or designs that remove the need for chemical flame retardants (see INF document related to this paper).
Chemical substitutes for c-OctaBDE in ABS plastic
The report “Risk Reduction Strategy and Analysis of Advantages and Drawbacks for Octabromodiphenyl Ether” (RPA, 2002) preceding the EU level control measures contains an analysis on the suitability of various alternatives to c- OctaBDE in terms of technical performance, health and environmental risks and cost implications. Potential alternatives identified include tetrabromobisphenol-A, 1,2-bis(pentabromophenoxy) ethane, 1,2-bis(tribromophenoxy) ethane, triphenyl phosphate, resourcinol bis (diphenylphosphate) and brominated polystyrene.
In ABS, TBBPA and brominated epoxy oligomers are used as additive flame retardants meaning that they are not bound to the polymer and therefore have a greater tendency to be released to the environment. TBBPA is a cytotoxicant, immunotoxicant, and thyroid hormone agonist with the potential to disrupt estrogen signaling (Birnbaum and Staskal, 2004). TBBPA is classified as very toxic to aquatic organisms and is on the OSPAR Commission’s List of Chemicals for Priority Action due to its persistence and toxicity (RPA, 2002; OSPAR, 2005) . To avoid their use in ABS applications, poly (phenylene oxide) / high impact polystyrene (PPO / HIPS) blends flame retarded with resorcinol diphosphate (RDP) have been proposed (Morose, 2006).
Bisphosphate and its derivatives include RDP and are used in “Blue Angel” printers and PCs with PC / ABS casings (Leisewitz et al., 2000). The US EPA DfE report lists triaryl phosphate and an isopropylated derivative as having moderate bioaccumulation properties based on structure activity relationships (US EPA, 2005). Bis (tribromophenoxy) ethane is poorly characterized. Studies by its manufacturer indicate low toxicity, but the substance tends to persist and bioaccumulate (Washington State, 2005).
Chemical substitutes for c-OctaBDE in synthetic textiles
Reactive-type flame retardants are usually used in thermosetting material (e.g. polyester resins, epoxy resins, polyurethanes). Chemical substitutes for c-OctaBDE in textiles include reactive phosphorous constituents and hexabromocyclododecane. Specific reactive phosphorous constituents were not identified in a Danish report though polyglycol esters of methyl phosphonic acid (CAS 676-97-1) have been used for flame retardants in polyurethane foam (e.g. CAS 294675-51-7) (Danish Environmental Protection Agency, 1999). Methyl phosphonic acid has attracted attention of those working on chemical weapons since it is a degradation product of VX, sarin, and soman (OPCW, 2006). Researchers at the Oak Ridge National Laboratory in the US describe methyl phosphonic acid as one of degradation products of chemical weapons with “significant persistence”(Munro et al. 1999a), However, methyl phosphonic acid does not appear to be bioaccumulative (Munro et al. 1999b). Other types of reported toxicity are minimal, but the substance reacts violently with water (US EPA, 1985). The phosphonic acid family also includes amino-methyl phosphonic acid, a degradation product of the herbicide glyphosate (also known as [carboxymethylamino] methyl phosphonic acid.)
Hexabromocyclododecane (HBCD) is used as an additive flame retardant indicating that it is not bound to the polymer and therefore has a greater tendency to be released to the environment. HBCD is bioaccumulative, persistent, and causes neurobehavioral alterations in vitro (Birnbaum and Staskal, 2004).
Chemical substitutes for c-OctaBDE in thermoplastic elastomers
Additive-type flame retardants are usually used in thermoplastic material (e.g. Polypropylen, Polyethylen, Ethylen- Vinylacetate, PVC).
Chemical substitutes for c-OctaBDE in thermoplastic elastomers include bis (tribromophenoxy) ethane and tribromophenyl allyl ether (Danish Environmental Protection Agency, 1999). Bis (tribromophenoxy) ethane is discussed above under alternatives for c-OctaBDE in ABS plastic. Very little information was available for tribromophenyl allyl ether, though it is on a list of flame retardants considered “deferred” for testing by the interagency testing committee of US EPA (IPCS, 1997).
Chemical substitutes for c-OctaBDE in polyolefins
Chemical substitutes for c-OctaBDE in polyolefins include polypropylene-dibromostyrene, dibromostyrene, and tetrabromobisphenol A (TBBPA) (Danish Environmental Protection Agency, 1999). TBBPA is described above in chemical substitute alternatives for c-OctaBDE in ABS plastic. Few data are available for dibromostyrene and polypropylene-dibromostyrene. For dibromostyrene, an EU assessment found insufficient information on toxicity, no bioaccumulation based on a low BCF value, and overall persistence of 49 days based on modelling (Pakalin et al., 2007).
Technical feasibility
All above described alternatives to c-OctaBDE are technically feasible and have been used in commercial applications.
The EU RPA concludes, “Based on consultation with industry, it is evident that most companies have already replaced octabromodiphenyl ether in their products with other flame retardants and some companies utilise design measures, rather than flame retardants, for certain types of products. Overall, there does not appear to be any major technical obstacle to replacement of the substance, although some of the flame retardant/polymer combinations considered in this section may have inferior technical performance in certain applications” (RPA, 2002).
Many high profile companies have already implemented alternatives to c-OctaBDE. For example, Dell (#1 in US PC sales) eliminated all halogenated flame-retardants in all desktop, notebook and server chassis plastic parts in 2004 and has recently expanded these restrictions to include all products designed after June 2006 (Greiner et al., 2006). Lenovo (#6 in US PC sales) has eliminated PBDEs including c-OctaBDE in all of their products (Pierce, 2006). LG Electronics (#8 in US TV sales) plans to eliminate all brominated flame retardants by 2010 (Clean Production Action, 2006). A comparison of computer, TV, and game manufacturers on their BFR phase-out timelines and BFR-free products has also been assembled by Greenpeace and is updated every three months (Greenpeace International, 2007).
Additional companies that have phased out PBDEs in all their products include: IBM, Ericsson, Apple, Matsushita (including Panasonic), Intel, and B&O (Lassen et al., 2006).
For further information, please refer to
- UNEP/POPS/POPRC.5/10/Add.1 – General guidance on considerations related to alternatives and substitutes for listed persistent organic pollutants and candidate chemicals
- Risk profile Ar, Ch, En, Fr, Ru, Sp (PDF)
- Risk management evaluation Ar, Ch, En, Fr, Ru, Sp (PDF)