Difference between revisions of "Tetrabromobisphenol A"

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{{Definition|title=tetrabromobisphenol–A
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{{Definition|title=tetrabromobisphenol–A(TBBP-A)
  
|definition=Tetrabromobisphenol–A (TBBP-A) is a brominated organic compound. It's primary used as an intermediate in the production of [[flame retardants]] like [[PBDE|PBDEs]], but can also be used as a flame retardant itself. <ref name="Ospar">[http://www.ospar.org/documents%5Cdbase%5Cpublications%5Cp00202_BD%20on%20TBBPA.pdf OSPAR Commission, 2005: OSPAR background document on tetrabromobisphenol-A]</ref>
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|definition=Tetrabromobisphenol–A is a brominated organic compound. It's primary used as an intermediate in the production of [[flame retardant|flame retardants]] like [[PBDE|PBDEs]], but can also be used as a flame retardant itself<ref name="Ospar">[http://www.ospar.org/documents%5Cdbase%5Cpublications%5Cp00202_BD%20on%20TBBPA.pdf OSPAR Commission, 2005: OSPAR background document on tetrabromobisphenol-A]</ref>.
 
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}}
 
  
 
== Notes ==
 
== Notes ==
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Tetrabromobisphenol-A is produced in the USA, Israel and Japan but not in the EU. Current production is estimated between 120.000 and 150.000 ton each year, of which approximately 40.000 ton is each year exported to the European Union.
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Tetrabromobisphenol-A is produced in the USA, Israel and Japan but not in the EU. Current production is estimated between 120.000 and 150.000 ton each year, of which approximately 40.000 ton is exported to the European Union.
 
 
Tetrabromobisphenol-A is likely to reach the marine environment largely through industrial waste waters
 
from land-based industrial activities. A smaller contribution to releases to water comes from particulate
 
losses from products containing the substance over their lifetime. Emissions to air are smaller than those to
 
water, and most such emissions are expected to be deposited close to the sources of emission. There are
 
however some indications of possible transport over longer distances, possible adsorbed to particulate
 
matter, which could lead to a contribution to the marine environment through this route.
 
 
 
No data are available on loads of tetrabromobisphenol-A entering the OSPAR Convention Waters and the
 
Greater North Sea.
 
 
 
 
 
There are no available measured levels of tetrabromobisphenol-A in marine waters, but there are
 
measurements in estuarine sediments, as well as in freshwaters, freshwater sediments and waste waters. A
 
summary of these data2 is included in Tables 2 to 4.
 
The available data on the levels of tetrabromobisphenol-A in aquatic biota are summarised in Table 5.
 
 
 
 
 
 
 
Tetrabromobisphenol-A is not considered to fully meet the PBT criteria as its liability to biaccumulate is
 
below the threshold set by OSPAR. It is, however, persistent and toxic.
 
The potential for
 
tetrabromobisphenol-A to degrade under anaerobic conditions to form bisphenol-A is also still being
 
investigated within the ESR process. Tetrabromobisphenol has been detected in freshwater, freshwater
 
sediments and estuarine sediments but there are no available measured levels in marine waters. It has
 
been detected in marine biota
 
 
 
 
 
 
 
The classification of tetrabromobisphenol-A against the EC Technical Guidance Document PBT criteria
 
gave the following results:
 
Persistence: tetrabromobisphenol-A is not considered to be readily biodegradable in the risk assessment,
 
hence it meets the screening criteria for P or vP.
 
 
 
Bioaccumulation: the highest measured BCF value for fish is 1 234 l/kg, and there are several other
 
determinations below this value. This value is below the cut-off value of 2 000, and so tetrabromobisphenol-
 
A does not meet the B criterion.
 
 
 
Toxicity: the toxicity criterion used in the marine risk assessment guidance is a chronic NOEC <0,01 mg/l.
 
There is some uncertainty over the actual NOEC for tetrabromobisphenol-A but the currently available data
 
indicate that the NOEC for tetrabromobisphenol-A is around 0,0026 mg/l. Based in this result, it can
 
provisionally be concluded that tetrabromobisphenol-A meets the toxicity criterion.
 
  
Conclusion of the PBT assessment
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Tetrabromobisphenol-A is likely to reach the marine environment through industrial waste waters from land-based industrial activities. A small contribution may come from releases to the water from losses from products which contain the substance<ref name="Ospar">[http://www.ospar.org/documents%5Cdbase%5Cpublications%5Cp00202_BD%20on%20TBBPA.pdf OSPAR Commission, 2005: OSPAR background document on tetrabromobisphenol-A]</ref>.
Tetrabromobisphenol-A meets two of the three criteria for the PBT assessment. Although the measured
 
BCF value is around 60% of the threshold value, it is considered to be a maximum value as it may include
 
accumulation of metabolites. There are also indications for some degradation of tetrabromobisphenol-A
 
under both aerobic and aerobic conditions. Overall, tetrabromobisphenol-A is not considered to meet the
 
PBT criteria.
 
  
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There is currently no information on levels of tetrabromobisphenol-A in marine waters, but there are
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measurements in [[estuary|estuarine]] sediments and in [[North Sea]] [[biota]]. Concentrations in the Scheldt estuary sediments range between 0,1 and 32 µg/kg [[wet weight]]. Concentrations in North Sea biota can reach up to 245 µg/kg wet weight in whiting fillet.
  
Tetrabromobisphenol-A is very toxic to aquatic organisms, it does not degrade readily in the environment
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Tetrabromobisphenol-A is considered to have a moderate tendency towards [[bioaccumulation]].
and shows a high accumulation in fish (BCF>100). The detailed properties of tetrabromobisphenol-A,
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It's is a very [[persistent]] substance. It's very difficult to be biodegraded in aerobic conditions, while it's still rather unknown whether it degrades in anaerobic conditions: it has been suggested that under anaerobic conditions TBBT-A may be biodegraded to [[bisphenol-A]]. <P>
including numerical values for toxicity, persistence and bioaccumulation are set out in the fact sheet at
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TBBP-A is a [[toxic]] substance as concentrations above 2,6 µg/l might already cause problems at chronic exposure for marine invertebrates. Such concentrations might already impair the shell growth of a [[species]] of oysters. Fresh water invertebrates and fish have a higher tolerance, concentrations of 0,12 and 0,16 mg/l respectively are necessary to cause effects.
Appendix 2. This fact sheet includes the more recent values which have come to light in the RAR. TBBPA
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Present marine concentrations are considered to be of little risk to [[biota]], however concern is raised about the possible degradation to biphenol-A, of which low concentrations have been shown to affect the [[endocrine system]]<ref name="Ospar">[http://www.ospar.org/documents%5Cdbase%5Cpublications%5Cp00202_BD%20on%20TBBPA.pdf OSPAR Commission, 2005: OSPAR background document on tetrabromobisphenol-A]</ref>.
has demonstrated no endocrine disrupting effects in any of the tests available.
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<P>
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<BR>
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<P>
  
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== Environmental standards and legislation ==
  
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[[OSPAR List of priority substances|Included in the OSPAR list of substances of priority action]]
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<P>
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<BR>
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<P>
  
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== See also ==
  
The overall data set for tetrabromobisphenol-A consists of NOEC values for freshwater fish (NOEC 0,16
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[http://www.vliz.be/projects/endis/EDnorth.php?showchemprop=true&showeffects=true&chemeffects=true&chemid=656 Tetrabromobisphenol-A on ED North Database]
mg/l), two species of freshwater invertebrates (lowest NOEC 0,12 mg/l), two species of marine invertebrates
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<P>
(lowest NOEC/EC10 = 0,0026 mg/l for shell regrowth in Crassostrea virginica), and one freshwater algal
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[http://www.ospar.org/documents%5Cdbase%5Cpublications%5Cp00202_BD%20on%20TBBPA.pdf OSPAR background document on Tetrabromobisphenol-A ]
species (NOEC ≥5,6 mg/l). In addition acute EC50 values (but no NOEC values) are available for one
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<P>
freshwater algal species and three marine water algae (lowest EC50 is 0,09 mg/l). The substance has been
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<BR>
shown to have little or no estrogenic activity in the fish, invertebrates and amphibians tested so far. There is
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<P>
some evidence that the toxicity of tetrabromobisphenol-A to marine algae may increase with decreasing pH
 
in the range pH 7,6 to 8,2, but, given that natural seawater is effectively buffered at around pH 8 such trends
 
in toxicity are not likely to be important in reality.
 
  
From the Technical Guidance Document an assessment factor of 50 could be applied to the available data
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==References==
as there are NOECs from freshwater/marine species covering three trophic levels (algae, fish and
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<references/>
crustaceans) with in addition a long-term NOEC from an additional marine taxonomic group (molluscs). As
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{{author
marine as well as fresh water species have been tested in two of the trophic levels (algae and crustaceans)
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|AuthorID=19826
it could be considered to reduce the assessment factor to a value of 10. However, there is some uncertainty
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|AuthorFullName=Daphnis De Pooter
over the actual NOECs for some of the species tested (see main risk assessment report) and no NOEC has
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|AuthorName=Daphnisd}}
been determined for marine algae. The uncertainty over the NOECs means that it is not currently possible to
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[[Category:Coastal and marine pollution]]
derive a reliable PNEC for the aquatic compartment.
 
Therefore an assessment factor of 50 will be used on the extrapolated EC10 of 0,0026 mg/l for Crassostrea
 
virginica to derive an indicative value of 0,052 μg/l for the marine risk assessment.
 

Revision as of 16:37, 20 March 2013

Definition of tetrabromobisphenol–A(TBBP-A):
Tetrabromobisphenol–A is a brominated organic compound. It's primary used as an intermediate in the production of flame retardants like PBDEs, but can also be used as a flame retardant itself[1].
This is the common definition for tetrabromobisphenol–A(TBBP-A), other definitions can be discussed in the article

Notes

tetrabromobisphenol–A
TBBP-A.jpg
Formula
C15H12Br4O2

Tetrabromobisphenol-A is produced in the USA, Israel and Japan but not in the EU. Current production is estimated between 120.000 and 150.000 ton each year, of which approximately 40.000 ton is exported to the European Union.

Tetrabromobisphenol-A is likely to reach the marine environment through industrial waste waters from land-based industrial activities. A small contribution may come from releases to the water from losses from products which contain the substance[1].

There is currently no information on levels of tetrabromobisphenol-A in marine waters, but there are measurements in estuarine sediments and in North Sea biota. Concentrations in the Scheldt estuary sediments range between 0,1 and 32 µg/kg wet weight. Concentrations in North Sea biota can reach up to 245 µg/kg wet weight in whiting fillet.

Tetrabromobisphenol-A is considered to have a moderate tendency towards bioaccumulation.

It's is a very persistent substance. It's very difficult to be biodegraded in aerobic conditions, while it's still rather unknown whether it degrades in anaerobic conditions: it has been suggested that under anaerobic conditions TBBT-A may be biodegraded to bisphenol-A.

TBBP-A is a toxic substance as concentrations above 2,6 µg/l might already cause problems at chronic exposure for marine invertebrates. Such concentrations might already impair the shell growth of a species of oysters. Fresh water invertebrates and fish have a higher tolerance, concentrations of 0,12 and 0,16 mg/l respectively are necessary to cause effects. Present marine concentrations are considered to be of little risk to biota, however concern is raised about the possible degradation to biphenol-A, of which low concentrations have been shown to affect the endocrine system[1].


Environmental standards and legislation

Included in the OSPAR list of substances of priority action


See also

Tetrabromobisphenol-A on ED North Database

OSPAR background document on Tetrabromobisphenol-A


References

The main author of this article is Daphnis De Pooter
Please note that others may also have edited the contents of this article.

Citation: Daphnis De Pooter (2013): Tetrabromobisphenol A. Available from http://www.coastalwiki.org/wiki/Tetrabromobisphenol_A [accessed on 20-04-2024]