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A flame retardant is a chemical substance which is applied to a material (plastic, wood, fabric or other material in order to make it more resistant to catching fire. Bis(pentabromophenyl) ether (decaBDE) is one member of the family of the polybrominated diphenylethers (PBDE). It is used in in a broad range of plastic types and in textiles but uses in adhesives, sealants, coatings and inks are also reported. In the textile industry, it is generally back coated onto the textile in a latex binder. The product is a solid with a very low water solubility and vapor pressure. In the EU, currently used decaBDE is imported and it is possible that further amounts could be imported into or exported from the EU in finished articles or master batches.
According to the European Chemicals Agency (ECHA) , exposure to decaBDE, and distribution in humans (including prenatal exposure) and the environment are widespread and its persistence, creates a high potential for long-term (lifetime) exposure to decaBDE itself but also to lower brominated PBDE (polybrominated diphenyl ether) transformation products. In the EU, emissions are predominantly associated with the service life, rather than the production or waste stage, of plastic and textile articles. Local releases to the environment may occur from polymer processing and use in textile finishing. In addition, volatilization and leaching of the flame retardant from articles and also release of dust and particulates containing decabromodiphenyl ether, may occur during the lifetime of the article (and at disposal for particulates). Despite the voluntary risk management measures already taken by industry and the implementation of legislative measures, no recent increasing or decreasing trend in concentrations in bird eggs, sediments and sewage sludge were observed.
The potential exposure sources for decaBDE are ingestion of house dust and inhalation of airborne particulates as well as direct contact with consumer products. There is growing evidence that occupancy in cars and potentially in aeroplanes may be a significant source of exposure to polybromo BDE. The levels reported on a lipid basis seem to be quite similar in foetuses, children and adults throughout the world. Young children of age 1 – 3 years appear to be the age group with the highest exposures.
Significantly higher concentrations are seen in occupationally exposed persons but the data available are limited to high exposure occupation groups, like electronics dismantlers in Europe or firefighters.
1 ECHA - ANNEX XV PROPOSAL FOR A RESTRICTION –
Bis(pentabromophenyl) ether 2014
https://echa.europa.eu/documents/10162/a3f810b8-511d-4fd0-8d78-8a8a7ea363bc
https://echa.europa.eu/substance-information/-/substanceinfo/100.013.277
According to ECHA, DecaBDE meets the definitions of a Persistent, Bioaccumulable and Toxic(PBT) and of a very Persistent-very Bioaccumulable (vPvB) substance. Experience with PBT/vPvB substances has shown that they give rise to specific concerns due to their potential to accumulate in the environment and cause effects that are unpredictable in the long-term and difficult to reverse even when emissions cease.
Several epidemiological studies, not specific to decaBDE, support the notion that exposure to polybromo BDEs (PBDE), either alone or in combination, may result in human neurodevelopmental toxicity in mammals including humans. In particular, exposure to decaBDE and lower brominated transformation products may also result in neurotoxicity.
Meanwhile, according to the conclusion of a report from the European Food Safety Agency (EFSA)2, DecaBDE given to experimental animals during gestation and/or postnatally, at doses up to 500 mg/kg bw/day did not generally cause reproductive effects.
According to the same report, the available genotoxicity studies indicated that PBDEs do not induce gene mutations, but that they can cause DNA damage through the induction of reactive oxygen species.
2 EFSA - Scientific Opinion on Polybrominated
Diphenyl Ethers (PBDEs) in Food EFSA Journal 2011;9(5):2156
The epidemiological studies (studies on human groups) suggest that exposure to PBDEs may be associated to (sub)clinical hyperthyroidism and altered neuropsychological functioning: motor, cognitive and behavioral performance, or mental and physical development in children. However, the observed effects on thyroid hormone levels were not always consistent, and exposure to other halogenated contaminants could have confounded the outcome of these studies.
Due to the high uncertainties regarding long-term exposure to PBT/vPvB substances such as decaBDE, the effects and the level of risks to humans via the environment cannot be adequately addressed in a quantitative way.
Concerning more specifically dietary exposure, EFSA concluded in 2011 that some polybrominated BDE congeners (BDE-47, -153 and -209) do not raise a health concern in the EU while for congener BDE-99 there is a potential health concern with respect to current dietary exposure.
Based on the available data for fish and algae, decaBDE appears to have a very low toxicity in acute tests, with no effects being seen up to the substances water solubility. Visual observations carried out during the test revealed no signs of treatment-related phyto-toxicity toxicity for plants) , in any species and at any treatment level. No effects are expected at concentrations up to the water solubility of the substance and the risk to the aquatic compartment (surface water) from decaBDE itself can be considered to be low.
A EU risk assessment3 of decaBDE from all sources concluded that there was no need for further information and/or testing or for risk reduction measures beyond those which are already being applied for the environmental assessment of risks to the aquatic (surface water, sediment and wastewater treatment plants), terrestrial and atmospheric compartments.
There is however considerable uncertainties on the indirect risk to predators (secondary poisoning) and thus a need for further information and/or testing on such potential secondary poisoning from all sources of decaBDE. Furthermore, although the substance is persistent, there is evidence that it can also degrade under some conditions to more toxic and bioaccumulable compounds. If formed, these are likely to be only minor products, but there is some uncertainty over the actual significance of the process in the environment and it is currently not possible to quantify the actual risk from these processes.
Almost 200 substances that could potentially be alternatives to decaBDE were identified. A screening exercise subsequently undertaken to prioritize the most relevant alternatives on the basis of technical and economic feasibility, relative hazard (to decaBDE) and availability, shortlisted 13 alternatives. They are all marketed and currently in use, and it is considered in the ECHA report that all of them (and many others that were not assessed in detail) may be used in greater volumes if decaBDE was not available. Currently, only brominated flame retardants would appear to be able to act as drop-in replacements for decaBDE in a wide range of applications. It cannot be excluded that some users of decaBDE will switch to alternative techniques rather than alternative substances.
The combination of uncertainties raises a concern about the possibility of long-term environmental effects that cannot easily be predicted. The inherent difficulties and time required to complete the work lead to consider precautionary risk reduction action for this endpoint and thus to consider regulatory measures and policies.
This proposal is underpinned by the conclusions on the intrinsic hazard (i.e. PBT/vPvB toxic properties) of decaBDE. DecaBDE is known to undergo long-range transport and emissions from one Member State that could result in exposure in another, regardless of efforts of that Member State to reduce exposures within their own borders (i.e. through national legislation). To limit the potential for trans-boundary exposure to decaBDE from EU sources, both within and outside the EU is thus the primary reason to act on an E.U.-wide basis to effectively reduce the environmental exposure to decaBDE.
In addition, the fact that goods need to circulate freely within the EU stresses the importance of EU-wide action rather than action by individual Member States. From an effectiveness perspective, a restriction of the manufacture and use of both plastics and textile articles for both indoor and outdoor uses is considered as the most appropriate restriction option.
Nevertheless, the restriction should not negatively affect recycling activities and, after consultation with the European Aviation Safety Agency (EASA), derogations in the restrictions of DecaBDE uses were included for some specific applications in aviation.
In 2015, the Committee for Socio-economic Analysis ( SEAC) confirmed its draft opinion that the proposed restriction was the most appropriate EU-wide measure, in terms of the proportionality of its socio-economic benefits to its socio-economic costs with additional derogations for military aircraft, road vehicles, and spare parts for machinery and agricultural and forestry vehicles.
On February 2017, the Official Journal of the European Union published
Regulation (EU) 2017/227
4
SEAC restriction proposal on DecaBDE (bis(pentabromophenyl)ether)
5
http://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:32017R0227&from=EN
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