Bisphenol A
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| Bisphenol A | |
|---|---|
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| General | |
| Systematic name | 4,4'-dihydroxy-2,2-diphenylpropane |
| Other names | BPA, 4,4'-(propan-2-ylidene)diphenol, p,p'-isopropylidenebisphenol |
| Molecular formula | C15H16O2 |
| Molar mass | 228.29 g/mol |
| SMILES | CC(c2ccc(O)cc2)(C)c1ccc(O)cc1 |
| Appearance | free-flowing prills |
| CAS number | [80-05-7] |
| Properties | |
| Density and phase | 1.20 g/cm³, solid |
| Solubility in water | ? g/100 ml (? °C) |
| Melting point | 157 °C (430 K) |
| Boiling point | 220 °C (493 K) |
| Viscosity | ? cP at ? °C |
| Structure | |
| Molecular shape | ? |
| Crystal structure | ? |
| Dipole moment | ? D |
| Hazards | |
| MSDS | External MSDS |
| Main hazards | ? |
| Flash point | 207 °C, autoignition: 600 °C |
| R/S statement | R: 36, 37, 38, 43 S: 24, 26, 37 |
| RTECS number | ? |
| Supplementary data page | |
| Structure & properties | n, εr, etc. |
| Thermodynamic data | Phase behaviour Solid, liquid, gas |
| Spectral data | UV, IR, NMR, MS |
| Related compounds | |
| Related ? | ? |
| Related compounds | phenols |
| Except where noted otherwise, data are given for materials in their standard state (at 25°C, 100 kPa) Infobox disclaimer and references |
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Bisphenol A is a chemical compound with two phenol functional groups in its molecule that belongs to the phenol class of aromatic organic compounds. It is prepared by reaction of two equivalents of phenol with one equivalent of acetone.
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[edit] History and use
Bisphenol A was first synthesized by A.P. Dianin in 1891.[1][2] Bisphenol A was investigated in the 1930s during the search for synthetic estrogens. At that time, another synthesized compound, diethylstilbestrol, turned out to be more powerful an estrogen, so bisphenol A was not used as a synthetic estrogen.
Its current uses are as a primary monomer in polycarbonate plastic and epoxy resins. Bisphenol A is also used as an antioxidant in plasticizers and as a polymerization inhibitor in PVC.
Polycarbonates are widely used in many consumer products, from sunglasses and CDs to water and food containers and shatter-resistant baby bottles. Some polymers used in dental fillings also contain bisphenol A, while epoxy resins containing bisphenol A are popular coatings for the inside of cans used for canning food.
[edit] Possible health risks
Bisphenol A is known to be an estrogen receptor agonist which can activate estrogen receptors leading to similar physiological effects as the body's own estrogens.[3] The first evidence of the estrogenicity of bisphenol A came from experiments in the 1930s in which it was fed to ovariectomised rats.[4][5] Some hormone disrupting effects in studies on animals and human cancer cells have been shown to occur at levels as low as 2-5 ppb (parts per billion). It has been claimed that these effects lead to health problems such as, in men, lowered sperm count and infertile sperm. Recent studies have confirmed that bisphenol A exposure during development has carcinogenic effects and produce precursors of breast cancer.[6] Bisphenol A has been shown to have developmental toxicity, carcinogenic effects, and possible neurotoxicity. [7][8] Recent studies suggest it may also be linked to obesity by triggering fat-cell activity. [9]
Various environmental groups have claimed that studies show risks for human ingestion, and on the other hand, critics assert that bisphenol A is safe. Government regulatory agencies in Europe, Japan, and the United States have all concluded that normal use of polycarbonates containing bisphenol-a poses no health risk.[10] In January 2006, the German Federal Institute for Risk Assessment announced that polycarbonate baby bottles are safe, stating that published research is "difficult to interpret and [is] occasionally contradictory".[11] Subsequent study by European Union’s Food Safety Authority reached similar conclusion, and sharply criticized the methodology used in many of the low-dose exposure studies on rodents.[12] However, recent reports in media point to the fact that scientific panels that investigate safety of such chemicals have industry ties, and might be biased in publishing such reports.[13] Furthermore, peer reviewed publications have appeared pointing out flaws within the chemical industry funded studies that report bisphenol A safety.[14]
Bisphenol A has been known to leach from the plastic lining of canned foods and to a lesser degree plastics which are cleaned with harsh detergents or used to contain acidic or high temperature liquids.[15] Infants fed with concentrated (canned) infant formula have among the highest exposures of anyone eating canned foods. Infants fed canned formula with polycarbonate bottles can consume quantities of bisphenol A up to 13 µg/kg/day.[16] The chemical is found in most people who live in developed countries at low concentrations. Debate continues on what is the safe limit of this compound. Within the United States, an exposure of up to 50 µg/kg/day (50 ppb) is considered safe by the EPA.[17]
[edit] References
- ^ Dianin, Zhurnal russkogo fiziko-khimicheskogo obshchestva, 23 (1891), pp. 492 ff.
- ^ Th. Zincke (1905). "Ueber die Einwirkung von Brom und von Chlor auf Phenole: Substitutionsproducte, Pseudobromide und Pseudochloride". Justus Liebigs Annalen der Chemie (343): 75-99. DOI:10.1002/jlac.19053430106.
- ^ O’Connor, Chapin (2003). "Critical evaluation of observed adverse effects of endocrine active substances on reproduction and development, the immune system, and the nervous system" (Full Article). Pure Appl. Chem 75 (11-12): 2099–2123. Retrieved on 2007-02-28.
- ^ E. C. Dodds and Wilfrid Lawson, Nature, 137 (1936), 996.
- ^ E. C. Dodds and W. Lawson, Proceedings of the Royal Society of London, Series B, Biological Sciences, 125, #839 (27-IV-1938), pp. 222-232.
- ^ Murray TJ (2007). "Induction of mammary gland ductal hyperplasias and carcinoma in situ following fetal bisphenol A exposure." (Abstract). Reproductive Toxicology. Retrieved on 2007-02-28.
- ^ Lee Ym, et al. (2007). "Estrogen receptor independent neurotoxic mechanism of bisphenol A, an environmental estrogen." (Abstract). J Vet Sci. 8 (1): 27-38. Retrieved on 2007-02-28.
- ^ Zsarnovszky A, Le HH, Wang HS, Belcher SM. (2005). "Ontogeny of rapid estrogen-mediated extracellular signal-regulated kinase signaling in the rat cerebellar cortex: potent nongenomic agonist and endocrine disrupting activity of the xenoestrogen bisphenol A" (Abstract). Endocrinology. 146 (12): 5388-96. Retrieved on 2007-02-28.
- ^ Grossman, Elizabeth. (March 12, 2007). "Chemicals May Play Role in Rise in Obesity.". Washington Post..
- ^ Why has bisphenol A not been banned? - Federal Institute for Risk Assessment
- ^ Selected questions and answers relating to bisphenol A in baby bottles- Federal Institute for Risk Assessment
- ^ European Safety Review: No Risk from Bisphenol A Exposure
- ^ [http://www.sun-sentinel.com/features/health/sfl-la-na-chemicals4mar04,0,2453959.story?coll=sfla-news-science Public health agency linked to chemical industry] - South Florida Sun-Sentinel
- ^ Frederick S. vom Saal (2006). "Large effects from small exposures. II. The importance of positive controls in low-dose research on bisphenol A." (Abstract). Environmental Research 100 (1): 50-76. Retrieved on 2007-02-28.
- ^ Environmental Working Group. Retrieved on 2007-03-07.
- ^ European Food Safety Authority Opinion (Abstract). Retrieved on 2007-02-28.
- ^ Bisphenol A - US EPA
[edit] External links
- Plastics chemical alters female brains
- News report on effect through plastic bottles
- Bisphenol A. A Known Endocrine Disruptor WWF publication
- Plastics Industry Bisphenol A information site
- EPA page on Bisphenol A
- An Endocrine/Estrogen Letter special Report on BPA
- News coverage of bisphenol A from EnvironmentalHealthNews.org
- EWG testing of Bisphenol A in canned food and formula
- Links to external chemical sources
