Risk Assessment of flame retardant decabromodiphenylether: no risk reduction mesures necessary, except for risks of secondary poisoning

Excerpts from the conclusions of the report selected by GreenFacts 

The full report is available on : http://tcsweb3.jrc.it/DOCUMENTS/Existing-Chemicals/RISK_ASSESSMENT/REPORT/decabromodiphenyletherreport013.pdf

Decabromodiphenyl ether is used as an additive flame retardant in a wide range of plastic types. In the textile industry, decabromodiphenyl ether is generally backcoated onto the textile in a latex binder. The product is a solid of very low water solubility and vapour pressure.  The decabromodiphenyl ether currently used in the EU is imported.

Local releases to the environment may occur from polymer processing and use in textile finishing. In addition, volatilisation and leaching of the flame retardant from articles, and also release of particulates containing decabromodiphenyl ether, may occur during the lifetime of the article (and at disposal for particulates). These releases have been quantified in the risk assessment and used to calculate the Predicted Environmental Concentrations (PECs) for various environmental compartments. It is possible that further decabromodiphenyl ether could be imported into (or exported from) the EU in finished articles or masterbatch.

Human health risk asessement conclusions

With regard to human health toxicity, for workers exposed to the substance, consumers, humans exposed via the environment or combined exposure, there is at present no need for further information and/or testing or for risk reduction measures beyond those which are being applied already.

Environmental risk assessment conclusions

An area of potential concern for both direct toxicity and secondary poisoning is the possible formation of brominated dibenzo-p-dioxins and dibenzofurans from articles containing the substance during combustion or other high temperature processes (e.g. incineration, landfill (where fires could occur) or accidental fires) Overall, it can be concluded that decabromodiphenyl ether, as a source of bromine, can contribute to the formation of halogenated dibenzo-p-dioxins and debenzofurans generated during such processes.

Based on the available data for fish and algae, decabromodiphenyl ether 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 phytoxicity in any species and any treatment level. No effects are expected at concentrations up to the water solubility of the substance. The risk to the aquatic compartment (surface water) from decabromodiphenyl ether itself can be considered to be low.

The available evidence indicates that the lower brominated diphenyl ethers, if formed, 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.

General conclusions of the EU risk assessment 

  There is at present no need for further information and/or testing or for risk reduction measures beyond those which are being applied already. This applies to the environmental assessment of risks to the aquatic (surface water, sediment and wastewater treatment plants), terrestrial and atmospheric compartments by the conventional PEC/PNEC ratio (Predicted Environmental Concentration/Predicted No Effect Concentration ratio) for decabromodiphenyl ether itself from all sources.

There is considerable uncertainties in the secondary poisoning assessment,and thus a need for further information and/or testing on secondary poisoning from all sources of decabromodiphenyl ether.  A strict PEC/PNEC approach may not be appropriate for this substance. In addition, the possibility of degradation in the environment to give more toxic lower brominated diphenyl ethers cannot be completely ruled out over extended time periods with the available data. The combination of uncertainties raises a concern about the possibility of long-term environmental effects that can not easily be predicted. Although further information is necessary to help clarify the concern, the inherent difficulties and time required to complete the work mean that there may be a need at a policy level to consider precautionary risk reduction action for this endpoint.  Possible areas for further work were considered in the conclusions of the report.

A second aspect of the concern for secondary poisoning is that although the substance is persistent, there is evidence that it can degrade under some conditions to more toxic and bioaccumulative compounds. An investigation of the rate of formation of degradation products under environmentally relevant conditions could be done.

Given the persistent nature of the substance, it would be of concern if, once the further information had been gathered, the analysis indicated a risk to predators, since it could then be difficult to reduce exposure. In summary, although it is concluded that further information should be gathered in order to refine the risk assessment, and given the fact that there is no guarantee that the studies would provide unequivocal answers, consideration should be given at a policy level about the need to investigate risk management options now in the absence of adequate scientific knowledge. The possible long-term increase in levels as a result of releases from waste sites might need to be considered further in any future revision of this risk assessment report.

 Results of the discussion of the Bis(pentabromophenyl) ether Risk assessment at the policy level

Member States noted the uncertainties expressed regarding the risk characterisation for secondary poisoning  and that the resulting refined risk assessment could then indicate a risk to predators. Consequently Member States agreed that emission reduction measures should be considered without delay for the sources of this exposure.

EUR 20402 EN – European Union Risk Assessment Report

Bis(pentabromophenyl) ether, Volume 17

IUPAC Name Bis(pentabromophenyl) ether

CAS Number: 1163-19-5

EINECS Number: 214-604-9

Editors: B.G. Hansen, S.J. Munn, J. de Bruijn, M.Luotamo, S. Pakalin, , F. Berthault, S. Vegro,

G. Pellegrini, R. Allanou, S. Scheer.

Luxembourg: Office for Official Publications of the European Communities

Note : the content of the shorts reports of the blog are not verified by the Scientific Board

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