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Brominated flame retardants; Toxicity and ecotoxicity
2. Results
Twelve substances (two were isomers) were selected for further
evaluation (table 2). The health and environmental assessment is presented
in appendix 2. The substances not assessed in this project because of
missing data in the preliminary data screening are listed in table 3. The
main conclusions on all evaluated compounds are presented in table 4.
Many of the data and conclusions of some of the BFR were found in well
recognised international evaluations/reviews, e.g. WHO's International
Programme on Chemical Safety and International Agency for Research on
Cancer. It was not possible to locate good national or international
assessments on all selected BFR, and many data were found in old and not
easily accessible documents. The validity of these tests varies and is
often not possible to evaluate. A thorough evaluation of each study was
not possible within the limits of this project.
The chemical composition of commercial PBDE products varies with
respect to purity and composition of isomers and impurities (see Appendix
2 and Table 5). The documentation of the selected PBDE (PeBDE, OBDE and
DeBDE) is seldom based on "pure" substances, and the purity of
the individual PBDE is often lower in old products compared to new
commercial products. Based on the typical composition of commercial PeBDE,
OBDE and DeBDE products, it appears difficult to extrapolate toxic effects
from one PBDE to another.
Table 2. Chemical substances subjected to health and environmental
assessment
| CAS No. |
Chemical name |
| 79-94-7 |
Tetrabromobisphenol A |
| 87-83-2 |
Pentabromotoluene |
| 118-79-6 |
2,4,6-Tribromophenol |
| 593-60-2 |
Vinyl bromide |
| 1163-19-5 |
Decabromodiphenylether |
| 3194-55-6 |
1,2,5,6,9,10-hexabromocyclododecane |
| 3296-90-0 |
2,2-Bis(bromomethyl)propane-1,3-diol |
| 13654-09-6 |
Decabromobiphenyl |
| 25637-99-4 |
Hexabromocyclododecane |
| 32534-81-9 |
Pentabromodiphenylether |
| 32536-52-0 |
Octabromodiphenylether |
| 88497-56-7 |
Brominated styrene homopolymer |
Table 3. Chemical substances with no or only very few data in the
preliminary data screening
| CAS No. |
Chemical name |
| 632-79-1 |
Tetrabromophtalic acid anhydride |
| 3234-02-4 |
2,3-Dibromo-2-butene-1,4-diol |
| 32588-76-4 |
Ethylene bis(tetrabromophtalimide) |
| 32844-27-2 |
TBBPA carbonate oligomer |
| 37853-59-1 |
1,2-bis(2,4,6-tribromophenoxy)ethane |
| 58965-66-5 |
1,2,4,5-tetrabromo-3,6-bis(pentabromophenoxy)benzene |
| 68441-62-3 |
Brominated polyetherpolyol |
Table 4. The main conclusions from the health and environmental
assessment
| CAS No. |
Chemicals and conclusions |
| 79-94-7 |
Tetrabromobisphenol A (TBBPA)
The data available do not indicate that TBBPA represent a special
health hazard to man.
Based on the available information, TBBPA is considered not
readily biodegradable. TBBPA is considered to be very toxic to
aquatic organisms, and it may cause long-term adverse effects in the
aquatic environment |
| 87-83-2 |
Pentabromotoluene (5BT)
The very few data available do not indicate that 5BT represent a
special health hazard to man.
Based on the available information, 5BT is considered not readily
biodegradable. |
| 118-79-6 |
2,4,6-Tribromophenol
Based on the available data it may be concluded that
2,4,6-tribromophenol indicate a possible risk of harm to the human
foetus.
The available data indicate that 2,4,6-tribromophenol is toxic to
aquatic organisms, and that it may cause long-term adverse effects
in the aquatic environment. |
| 593-60-2 |
Vinyl bromide
Vinyl bromide is considered to be potential carcinogenic and is
classified Carc 2;R45 Fx;R12 (Index No. 602-024-00-2 in Annex 1,
Council Directive 67/548/EEC)
No ecotoxicity and environmental fate data were available for
environmental assessment. |
| 1163-19-5 |
Decabromodiphenylether (DeBDE)
The data available do not indicate that DeBDE represent a special
health hazard to man.
Based the few data available, DeBDE is considered not readily
biodegradable. |
| 3194-55-6
25637-99-4 |
1,2,5,6,9,10-hexabromocyclododecane
Hexabromocyclododecane (HBCD)
There are some indications of a skin sensitising potential of
HBCD, and there may be risk of accumulation in adipose tissue and
effects on the liver and thyroid gland in case of repeated exposure.
Further research is needed for an adequate evaluation of these
effects.
Based on available data HBCD is considered to be very toxic for
aquatic organisms, and it may cause long-term adverse effects in the
aquatic environment. |
| 3296-90-0 |
2,2-Bis(bromomethyl)propane-1,3-diol (DBNPG)
Based on available data DBNPG may be considered harmful if
swallowed and potential carcinogenic.
No ecotoxicity or environmental fate data were available for
environmental assessment. |
| 13654-09-6 |
Decabromobiphenyl (DeBB)
There is some evidence for carcinogenicity of commercial mixtures
of PBB to experimental animals. Polybrominated biphenyls (PBB) are
in general considered to be potentially bioaccumulative.
Too few ecotoxicity and environmental fate data for DeBB were
available for environmental assessment. |
| 32534-81-9 |
Pentabromodiphenylether (PeBDE)
Studies in rodents with commercial preparations containing PeBDE
indicated that the liver is the key target organ affected. The
effects observed included macroscopic and histologic changes in
liver as well as induction of a range of liver enzymes, and
disturbances in cholesterol and porphyrin synthesis. Probably as a
consequence of the induction of liver enzymes, the thyroid gland was
also affected. Toxicokinetic studies in rats and mice indicate a
moderate retention in the organism, and traces have recently been
detected in human plasma, milk and fat tissue. Further research is
needed for an adequate evaluation of the observed effects.
Based on the few available data, PeBDE is considered not readily
biodegradable. |
| 32536-52-0 |
Octabromodiphenylether (OBDE)
Exposure of pregnant rats and rabbits to commercial OBDE products
of low OBDE purity and high HpBDE content indicated that the
foetuses were more sensitive than the dams. Evidence of
teratogenicity was found in one rat study, and OBDE may represent a
possible risk of harm to the human foetus.
Based on the few available data, OBDE is considered not readily
biodegradable. |
| 88497-56-7 |
Brominated styrene homopolymer
Brominated polystyrene is not a chemically well defined substance
and the molecular formula, (C8HxBry)z (x = 5-6, y = 2-3, z = 4-100),
indicates the existence of a range of different molecules. The high
molecular weight of the material indicates a low potential for
transport to the systemic circulation, and the associated toxicity
is considered very low. Monomers, solvents and other impurities may
account for the mutagenic potential found in some gene mutation
assays. The only impurity listed, ethylene dichloride (CAS No.
107-06-2), occurred at very low concentrations, but it is a well
known potential carcinogen.
No ecotoxicity or environmental fate data were available for
environmental assessment. |
Table 5. Typical chemical composition of selected PBDE (%)
| PBDE |
PeBDE |
OBDE |
DBDE |
| TrBDE |
0-1 |
|
| TeBDE |
24-38 |
|
| PeBDE |
50-60 |
10.5-12.0 |
| HxBDE |
4-8 |
|
| HpBDE |
|
43.7-44.5 |
| OBDE |
|
31.3-35.3 |
| NBDE |
|
9.5-11.3 |
Some |
| DeBDE |
|
0-0.7 |
97-98 |
Abbreviations see Appendix 1.
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