Brominated diphenyl ethers cas
A brominated flame retardant 2,2',4,4',5-pentabromodiphenyl ether: uptake, retention and induction of neurobehavioral alterations in mice during. Polybrominated diphenyl ethers (PBDE) have a large number of congeners, depending on the number and position of the bromine atoms on the two phenyl rings. The. The congener brominated diphenyl ether- (BDE) is a high-bromine polybrominated diphenyl ether (PBDE) and a common flame retardant. VALUE INVESTING STRATEGIES AND FUNDAMENTAL ANALYSIS PDF
Crit Rev Toxicol ;16 2 Polybrominated diphenyl ethers: human tissue levels and toxicology. Rev Environ Contam Toxicol ; Hallgren S, Darnerud PO. Polybrominated diphenyl ethers PBDEs , polychlorinated biphenyls PCBs and chlorinated paraffins CPs in rats-testing interactions and mechanisms for thyroid hormone effects.
Hardy ML. The toxicology of the three commercial polybrominated diphenyl oxide ether flame retardants. Chemosphere ;46 5 Is house dust the missing exposure pathway for PBDEs? An analysis of the urban fate and human exposure to PBDEs. Environ Sci Technol ;39 14 Polybrominated diphenyl ethers—plasma levels and thyroid status of workers at an electronic recycling facility.
Int Arch Occup Environ Health ;78 7 Assessment of human exposure to polychlorinated biphenyls and polybrominated diphenyl ethers in Japan using archived samples from the early s and mids. Environ Res ;99 1 Developmental exposure to low dose PBDE effects on male fertility and neurobehavior in rat offspring. Environ Health Perspect ; 2 Analysis of polybrominated diphenyl ethers in Swedish human milk.
A time-related trend study, J Toxicol Environ Health A ;58 6 Geographical distribution and temporal trends of brominated diphenyl ethers in Great Lakes hewing gull eggs. Environ Sci Technol ;36 22 Risk Reduction Monograph No. Paris, France. Environ Health Perspect ; 9 Polybrominated diphenyl ether flame retardants in the U. J Occup Environ Med ;47 3 Brominated flame retardants in serum from U. Environ Sci Technol.
A review on human exposure to brominated flame retardants—particularly polybrominated diphenyl ethers. Environ Int ;29 6 Retrospective time-trend study of polybrominated diphenyl ether and polybrominated and polychlorinated biphenyl levels in human serum from the United States. Environ Health Perspect. Concentration of polybrominated diphenyl ethers PBDEs in household dust from various countries. Environ Sci Technol b;42 4 Polybrominated diphenyl ethers in house dust and clothes dryer lint.
Environ Sci Technol ;39 4 Toxicol Appl Pharmacol ; 1 Ultrastructural changes observed in rat ovaries following in utero and lactational exposure to low doses of a polybrominated flame retardant. Toxicol Lett ; 3 Brominated flame retardants in archived serum samples from Norway: a study on temporal trends and the role of age. Apparent half-lives of hepta- to decabrominated diphenyl ethers in human serum as determined in occupationally exposed workers. Environmental Protection Agency U.
Toxicol Sci ;81 2 Neonatal exposure to polybrominated diphenyl ether PBDE disrupts spontaneous behaviour, impairs learning and memory, and decreases hippocampal cholinergic receptors in adult mice. Toxicol Appl Pharmacol ; 2 December 31, Department of Ecology Publication No. Environmental release and behavior of brominated flame retardants. Liver 7. Miscellaneous 7. Toxicity of soot, char, and other waste products from combustion of DeBDE-containing polymers 7.
General population exposure 8. Occupational exposure 8. Skin sensitization 8. Neurotoxicity 8. Epidemiological studies 9. Recommendations 2. Kinetics and metabolism in laboratory animals and humans 1. OBDE 1. Pyrolysis of octabromodiphenyl ether 4. Pyrolysis studies with polymers containing octabromodiphenyl ether 4. Behaviour of octabromodiphenyl ether during processing 4. Bioaccumulation 4. Ultimate fate following use 5. Exposure of the general population 5.
Occupational exposure during manufacture, formulation or use 6. Single exposure 6. Oral: Rat 6. Dermal: Rabbit 6. Inhalation: Rat 6. Short-term exposure 6. Long-term exposure 6. Skin and eye irritation; sensitization 6. Skin irritation 6. Eye irritation 6. Teratogenicity, reproductive toxicity, and embryotoxicity 6. Teratogenicity 6. Mutagenicity and related end-points 6. DNA damage 6. Mutation 6.
Chromosomal effects 6. Carcinogenicity 6. Other special studies 6. Liver 6. Production levels and processes 4. Levels in the environment 5. General population exposure 6. Environmental transport, distribution and transformation 1. PeBDE 1. Workplace exposure studies 4. Sediment and sewage sludge 5. Fish and shellfish 5. Aquatic mammals 5. Terrestrial mammals 5. Birds 5. General population 6. Single exposures 7. Dermal 7. Reproductive toxicity, embryotoxicity and teratogenicity 7. TeBDE 1.
Soil and sediment 5. Environmental levels 4. Physical and chemical properties 1. Conclusions and recommendations 2. Biodegradation 5. Aquatic organisms 6. Reproductive toxicity, embryotoxicity, teratogenicity 6. Albert, Consultores Ambientales Asociados, S. In the interest of all users of the environmental health criteria documents, readers are kindly requested to communicate any errors that may have occurred to the Director of the International Programme on Chemical Safety, World Health Organization, Geneva, Switzerland, in order that they may be included in corrigenda, which will appear in subsequent volumes.
The data should be used in accordance with paragraphs and recommendations paragraph 90 of the Second FAO Government Consultation The Group reviewed and revised the draft criteria monograph and made an evaluation of the risks for human health and the environment from exposure to brominated diphenyl ethers. The first draft of the monograph was prepared by Dr G. Head of Oxford, England, for the editing.
The fact that industry made proprietary toxicological information available to the IPCS and the Task Group on the products under discussion is gratefully acknowledged. This allowed the Task Group to make its evaluation on a more complete data base. The efforts of all who helped in the preparation and finalization of the document are gratefully acknowledged. The group of polybrominated diphenyl ethers PBDE has been selected as a priority because of the recent interest in these substances.
Only products based on penta-, octa-, and decabromodiphenyl ethers are of commercial interest. The general chemical formula of brominated diphenyl ethers is: Polybrominated diphenyl ethers PBDE have a large number of congeners, depending on the number and position of the bromine atoms on the two phenyl rings.
The total number of possible congeners is , and the numbers of isomers for mono-, di-, tri- up to decabromodiphenyl ethers are: 3, 12, 24, 42, 46, 42, 24, 12, 3, and 1, respectively. The commercial PBDE are produced by the bromination of diphenyl oxide under certain conditions, which result in products containing mixtures of brominated diphenyl ethers see the individual PBDE.
Flame retardants containing predominantly penta-, octa- and decabromodiphenyl ethers are commercially produced with tetrabromodiphenyl ether as a major component of "pentabromo-diphenyl ether", which is a mixture. Table 1. Analysis of one single sample. Many reports have appeared in the literature describing the behaviour of brominated flame retardants under pyrolytic conditions. Processing of the polymers under abusive or extreme conditions produced higher levels of PBDF, but the concentrations were significantly lower than the values previously reported from laboratory pyrolysis studies.
The 2,3,7,8-brominated isomers, which are of concern for toxicological and regulatory reasons, were not detected under normal processing conditions. Behaviour of PBDE is strongly dependent upon the polymer matrix and upon the specific processing conditions mentioned above, thus laboratory pyrolysis experiments can hardly be used as reliable models to predict behaviour in commercial moulding operations.
For details, see Table 2. In general, sample extraction and clean-up techniques for the analysis of PBDE residues in biological samples are similar to those developed for PBB see EHC Polybrominated biphenyls , though the chromatographic conditions have to be modified in view of the long retention times of the highly brominated PBDE.
Temperature programming and the use of capillary columns have been found to be very useful for the separation of the different congeners of PBDE. A multi-residue method has also been developed that includes a multi-step separation enabling the determination of several polychlorinated and polybrominated pollutants in biological samples Jansson et al.
Table 2. Table 3. Brominated diphenyl ethers are used as additive flame retardants. Additive flame retardants are incorporated into the plastic matrix like other additives, such as plasticizers. The ideal additive is inexpensive, colourless, easily blended, compatible, heat and light stable, efficient, permanent, and has no deleterious effect on the properties of the base polymer.
The most important limitations are incompatibilities that affect the physical properties of the polymers and the tendency for additives to be fugitive. These additive flame retardants are much more prone to leaching or escape from the finished polymer product than the reactive flame retardants Hutzinger et al.
The uses of penta-, octa-, and decabromodiphenyl ethers in the different resins, polymers, and substrates are shown in Table 4. The quantities used for each application are not publicly available. In consumer products, resins containing PBDE are typically used in interior parts, minimizing the potential for exposure of the public.
Table 4. Table 5. As discussed in EHC Polychlorinated dibenzo-para-dioxins and dibenzofurans, there are hundreds of possible congeners of halogenated dibenzofurans and dibenzo-dioxins. However, only congeners with substituents in the 2,3,7,8-positions are of toxicological significance. In many reports, only the total levels of PBDF and PBDD are given, without regard to substitution pattern; such totals are of limited value in the estimation of possible risk.
For more information on these pyrolysis experiments, see the different sections relating to the individual brominated diphenyl ethers, e. The vials were placed in a heated oven for about one minute, and the contents analysed. The next report to appear in the literature was also in from the laboratory of Hutzinger.
Hutzinger continued to investigate the pyrolysis of brominated flame retardants and brominated flame retardant polymer systems, and several publications appeared Thoma et al. Table 6. PBDF, however, may also be formed from small reactive species generated during PBDE cleavage Umweltbundesamt, ; Buser, see also the individual brominated diphenyl ethers.
Striebich et al. Thermal decomposition products were identified. Isomers with higher levels of bromination were generally more stable than lower brominated diphenyl ethers, under both oxidative and pyrolytic conditions. Table 7 shows the approximate yields of products from brominated diphenyl ethers. Table 7. Particulates in the respirable range are expected to be formed during the grinding of solids.
Exposure to these compounds can also take place during processing incorporation into various polymers and the use of the polymer blend to fabricate the final articles. After processing, the resin is generally in the form of pellets rather than powder. Exposure is expected to be low at fabrication sites because of the low vapour pressure and of ventilation controls US EPA, In the police traffic control office, air samples were taken for 3 days at a level of 1.
In the first room of a television company 50 m2 , where 58 monitors were in use, a total of m3 air was taken over 5 days. In the second room 40 m2 ,where 38 monitors were in use, m3 air was taken, while in the third room 30 m2 , where 42 monitors were in use, m3 air was taken. Dust samples were also collected once a day from all rooms using a vacuum cleaner. The concentrations in air of the police station and the television company ranged between 0. Remmers et al.
The presence of brominated diphenyl ethers was indicated in all of the 47 samples analysed Cramer et al. DeBDE was found in only a few samples at concentrations of 0. Exposure may also mainly occur through skin contact flame retardants in polymers used in textiles , but also via inhalation release of flame retardants from the polymer matrix US EPA, Four air samples 2 parallel to each other were taken over 3 days in a closed room volume One sampling was performed above the TV set, while the others were carried out in the centre of the room 2.
The levels in the centre of the room of tri-, tetra-, penta-, and hexabromo-dibenzofurans were 25, 2. Hepta- and octabromodibenzofuran, and poly-brominated dibenzodioxins were not found limits of determination 0. An investigation was conducted to determine the emissions of PBDE and PBDF from plastics in two TV sets, one colour and one monochrome, two computer monitors, and three printers, under conditions of use.
Analytical methods were refined to obtain a reliable determination of PBDF. Each appliance was placed, under conditions of use, in a test chamber. The volume of the steel chamber was 1. For three days, pure air was continuously drawn through the chambers at a rate of 1.
PBDF concentrations were found to vary between not detected limit of detection pg and pg per appliance tested and PBDE concentrations, between 0. Three new television sets were placed in a 1. Two of the cabinets were made from polystyrene, which was flame retarded with PBDF and PBDD concentrations were determined in air collected over 3 days while the two television sets were operating and during one day when the third TV set was operating.
After the fire test, samples of combustion residues and smoke condensate were taken. Smoke was collected in 5 tests. Residues and smoke condensates resulting from actual fire accidents with 9 TV sets were examined. Table 8. Table 9. Bearing in mind that PBDE, at least the congeners with more than 3 bromine atoms, are persistent in the environment, the introduction of such chemicals into widespread products may be a considerable long-term diffuse source of emissions of these compounds to the environment.
This type of source is difficult to control and the unnecessary use of persistent organic compounds should be avoided. They can also result from poorly-controlled combustion gas cooling. Lahl et al. Riggs et al. However, Oberg et al. Monobromodichloro-dibenzofuran levels were slightly increased.
They concluded that no unacceptable environmental risks were associated with the incineration of brominated compounds in plants with good combustion conditions equipped with efficient flue gas cleaning. They further noted that only 0. The concentrations in the air samples collected in Taiwan from a recycling plant in January were, in general, higher than those in Japan; 3 samples were analysed in Taiwan, and 5 in Japan.
Hepta- and octabromodiphenyl ether were not found Watanabe et al. Except for monobromo-diphenyl ether, levels of all the higher brominated PBDE were below the detection limit. PBDE were mainly found in river sediment. In these cases, the concentrations were much higher. In a river in Sweden, concentrations of A series of samples of sewage sludges from municipal waste water treatment plants in Germany were analysed for poly-halogenated compounds, such as halogenated diphenyl ethers.
Tribromo- to heptabromodiphenyl ethers were found at relatively high concentrations Hagenmaier et al. No data are available for HpBDE. The concentrations were much higher in fish collected in the vicinity of industrial areas, e. Mussels and fish in Japan contained up to Thirty-five samples of 18 freshwater fish collected in German rivers, and 17 samples collected from the Baltic Sea and the North Sea contained Limited data are available on the presence of PBDE in aquatic mammals.
The average concentration was 3. In Sweden, 2,2',4,4',5-PeBDE was found in the muscle tissue of osprey, in newborn starlings, and in guillemot eggs in concentrations of , 2. In the USA, indications were found that dibromodiphenyl ether was present in the eggs of fish-eating birds, but it was not quantified Stafford, The ages of the women ranged between 24 and 36 years and most of them were breast-feeding their first or second child.
The samples contained 0. The main component was HxBDE. One sample from a Chinese woman showed 7. This last value was excluded from the given range and average. Kruger, Nonabromodiphenyl ether NBDE is the major impurity. In contrast to the other polybrominated diphenyl ethers there is only one isomer of DeBDE. Commercial DeBDE has been produced in increasing degrees of purity since the late s. It is used as an additive flame retardant in many plastics, especially high-impact polystyrene, and in the treatment of textiles used in soft furnishing, automobile fabrics, and tents.
Photodegradation also occurs, to a lesser extent, in water with sunlight; however, lower brominated diphenyl ethers and brominated dibenzofurans have not been found. Levels of DeBDE extracted from polymers are close to, or below, the limit of detection, depending on the polymer type and extraction solvent. Because of its extremely low water solubility and vapour pressure, DeBDE is likely to be transported primarily by adsorption to particulate matter.
It is persistent and likely to accumulate in sediment and soil. No data are available on its bioavailability from sediment and soil. A study on rainbow trout did not show any bioaccumulation in flesh, skin, or viscera, over 48 h. DeBDE is unlikely to bioaccumulate because of its high relative molecular mass. Products containing commercial DeBDE will eventually be disposed of by landfill or incineration.
DeBDE may eventually leach from landfills. Polybrominated dibenzofurans PBDF and mixed halogen-dibenzofurans and -dibenzodioxins may result from landfill fires and inefficient incineration. Products containing commercial DeBDE may contribute to these emissions. In the absence of oxygen, mainly polybromobenzenes and polybromonaphthalenes are formed. DeBDE was not detected in water samples collected in Japan in the period DeBDE was not detected in fish samples collected in Japan, but, in one mussel sample, a level just above the level of detection was found.
Human exposure to DeBDE can occur in the course of manufacture and formulation into polymers. Exposure of the general population to DeBDE is insignificant. Determination of occupational exposure to the breakdown products of DeBDE during manufacture, formulation, or use, showed that air samples close to the extruder head contained high concentrations of PBDF. Lower levels were found in the air of the workroom.
PBDF was also found in wipe samples. The application of good engineering techniques has been shown to reduce occupational exposure to PBDF. Exposure of, the general population to PBDF impurities in flame retarded polymers is unlikely to be of significance.
The results of metabolic studies on the rat, using 14C labelled DeBDE, indicated a half-life for the disappearance from the body of less than 24 h and that the principal route of elimination following oral ingestion was via the faeces. Rats fed 0. Bromine accumulation in the liver plateaued at 30 days and was cleared within 10 days following treatment.
After days of treatment, the bromine level in the liver of treated rats was no greater than that in control rats. Adipose tissue accumulated low levels of total bromine, which remained after 90 days of clean diet; the nature of the retained "bromine" is not known. The substance is not an irritant to the skin or eyes of rabbits. It is not chloracnegenic on the skin of rabbits and is not a human skin sensitizer.
The combustion products of flame retarded polystyrene containing DeBDE and Sb were tested for acute toxicity and comedogenicity. DeBDE was not shown to be mutagenic in a number of tests. Female mice did not show any increase in tumour incidence. As the results of all mutagenicity tests have been negative, it can be concluded that DeBDE is not a genotoxic carcinogen. The very high dose levels, lack of genotoxicity, and minimal evidence for carcinogenicity indicate that DeBDE, at the present exposure levels, does not present a carcinogenic risk for humans.
Results of immunological studies showed that the immune system of the exposed persons was not adversely affected in 13 years. No further information is available on the effects of DeBDE on other organisms in the laboratory and field.
Contact of the general population is with products made from these polymers. Exposure is very low since the DeBDE is not readily extracted from polymers. The acute toxicity of DeBDE is very low and there is minimal absorption from the gastrointestinal tract. Thus, risk to the general population from DeBDE is considered to be insignificant. Occupational exposure is to DeBDE in particulate form.
The control of dust during manufacture and use will adequately reduce the risk for workers. DeBDE is persistent and binds to particulate matter in the environment; it is likely to accumulate in sediment. It is unlikely to bioaccumulate.
Current evidence suggests that environmental photodegradation in water does not lead to the formation of lower brominated diphenylethers or brominated dibenzofurans, but little is known about degradation in other media. There is minimal information on the toxicity of DeBDE for organisms in the environment. The possible hazards associated with this have to be addressed. Properly controlled incineration does not lead to the emission of significant quantities of brominated dioxins and -furans.
No adverse health effects have been associated with this exposure. Good engineering controls can prevent worker exposure to PBDF.
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