Bisphenol A | |
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4,4'-dihydroxy-2,2-diphenylpropane
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Other names
BPA, 4,4'-(propan-2-ylidene)diphenol,
p, p'-isopropylidenebisphenol, 4,4´-isopropylidenediphenol, 2,2-bis(4-hydroxyphenyl)propane. |
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Identifiers | |
CAS number | 80-05-7 ![]() |
PubChem | 6623 |
ChemSpider | 6371 |
EC number | 201-245-8 |
RTECS number | SL6300000 |
SMILES
Oc1ccc(cc1)C(c2ccc(O)cc2)(C)C
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InChI
InChI=1/C15H16O2/c1-15(2,11-3-7-13(16)8-4-11)12-5-9-14(17)10-6-12/h3-10,16-17H,1-2H3
Key: IISBACLAFKSPIT-UHFFFAOYAI |
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Properties | |
Molecular formula | C15H16O2 |
Molar mass | 228.29 g mol−1 |
Appearance | White to light brown flakes or powder |
Density | 1.20 g/cm³, solid |
Melting point |
158 to 159 °C (430 K) |
Boiling point |
220 °C (493 K) / 4 mmHg |
Solubility in water | 120–300 ppm (at 21.5 °C) |
Hazards | |
R-phrases | R36, R37, R38, R43 |
S-phrases | S24, S26, S37 |
NFPA 704 |
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3
0
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Flash point | 227°C |
Related compounds | |
Related compounds | phenols Bisphenol S |
![]() Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) |
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Infobox references |
Bisphenol A, commonly abbreviated as BPA, is an organic compound with two phenol functional groups used to make polycarbonate plastic and epoxy resins, along with other applications.
Known to be estrogenic since the mid 1930s, concerns about the use of bisphenol A in consumer products were regularly reported in the news media in 2008 after several governments issued reports questioning its safety, thus prompting some retailers to remove products containing it from their shelves. A 2010 report from the United States Food and Drug Administration (FDA) raised further concerns regarding exposure of fetuses, infants, and young children.[1]
Contents
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Bisphenol A was first reported by A.P. Dianin in 1891.[2][3]
It is prepared by the condensation of acetone (hence the suffix A in the name)[4] with two equivalents of phenol. The reaction is catalyzed by an acid, such as hydrochloric acid (HCl) or a sulfonated polystyrene resin. Typically, a large excess of phenol is used to ensure full condensation:
A large number of ketones undergo analogous condensation reactions. Commercial production of BPA requires distillation - either extraction of BPA from many resinous byproducts under high vacuum, or solvent-based extraction using additional phenol followed by distillation.[5]
Bisphenol A is used primarily to make plastics, and products containing bisphenol A-based plastics have been in commerce for more than 50 years. It is a key monomer in production of epoxy resins[6][7] and in the most common form of polycarbonate plastic.[5][8][9] Polycarbonate plastic, which is clear and nearly shatter-proof, is used to make a variety of common products including baby and water bottles, sports equipment, medical and dental devices, dental fillings and sealants, eyeglass lenses, CDs and DVDs, and household electronics.[10] BPA is also used in the synthesis of polysulfones and polyether ketones, as an antioxidant in some plasticizers, and as a polymerization inhibitor in PVC. Epoxy resins containing bisphenol A are used as coatings on the inside of almost all food and beverage cans,[11] however, due to BPA health concerns, in Japan epoxy coating was mostly replaced by PET film.[12] Bisphenol A is also a precursor to the flame retardant tetrabromobisphenol A, and was formerly used as a fungicide.[13] Bisphenol A is a preferred color developer in carbonless copy paper and thermal paper,[14] with the most common public exposure coming from some[15] thermal point of sale receipt paper.[16][17] BPA-based products are also used in foundry castings and for lining water pipes.[18]
Global production of bisphenol A was estimated to be over 2 million tonnes in 2003,[19] and more than 2.2 Mt in 2009.[20] In the U.S., it is manufactured by Bayer MaterialScience, Dow Chemical Company, SABIC Innovative Plastics (formerly GE Plastics), Hexion Specialty Chemicals, and Sunoco Chemicals. In 2004, these companies produced just over 1 million t of bisphenol A, up from just 7,260 t in 1991. In 2003, annual U.S. consumption was 856,000 t, 72% of which was used to make polycarbonate plastic and 21% going into epoxy resins.[10] In the US less than 5% of the BPA produced is used in food contact applications.[18]
There are seven classes of plastics used in packaging applications. Type 7 is the catch-all "other" class, and some type 7 plastics, such as polycarbonate (sometimes identified with the letters "PC" near the recycling symbol) and epoxy resins, are made from bisphenol A monomer.[5][21]
Type 3 (PVC) can also contain bisphenol A as an antioxidant in plasticizers.[5] This is particularly true for "flexible PVC", but not true for PVC pipes.
Type 6 (polystyrene) neither contains, nor does it break down into bisphenol A, according to the Styrene Information and Research Center, a not for profit organization whose membership represents approximately 95% of the North American styrene industry.[22]
Bisphenol A is an endocrine disruptor, which can mimic the body's own hormones and may lead to negative health effects.[23][24][25][26] Early development appears to be the period of greatest sensitivity to its effects.[27] Regulatory bodies have determined safety levels for humans, but those safety levels are currently being questioned or under review as a result of new scientific studies.[28][29]
The theory of endocrine disruption has been dismissed by some as junk science, with claims supported by politics and marketing, rather than research. [30] In 2009 the The Endocrine Society released a scientific statement expressing concern over current human exposure to BPA.[31]
In 2007, a consensus statement by 38 experts on bisphenol A concluded that average levels in people are above those that cause harm to many animals in laboratory experiments.[32] A panel convened by the U.S. National Institutes of Health determined that there was "some concern" about BPA's effects on fetal and infant brain development and behavior.[10] A 2008 report by the U.S. National Toxicology Program (NTP) later agreed with the panel, expressing "some concern for effects on the brain, behavior, and prostate gland in fetuses, infants, and children at current human exposures to bisphenol A," and "minimal concern for effects on the mammary gland and an earlier age for puberty for females in fetuses, infants, and children at current human exposures to bisphenol A." The NTP had "negligible concern that exposure of pregnant women to bisphenol A will result in fetal or neonatal mortality, birth defects, or reduced birth weight and growth in their offspring."[33]
A 2008 review has concluded that obesity may be increased as a function of BPA exposure, which "merits concern among scientists and public health officials".[34] A 2009 review of available studies has concluded that "perinatal BPA exposure acts to exert persistent effects on body weight and adiposity".[35] Another 2009 review has concluded that "Eliminating exposures to (BPA) and improving nutrition during development offer the potential for reducing obesity and associated diseases".[36] Other reviews have come with similar conclusions.[37][38]
A panel convened by the U.S. National Institutes of Health determined that there was "some concern" about BPA's effects on fetal and infant brain development and behavior.[10] A 2008 report by the U.S. National Toxicology Program (NTP) later agreed with the panel, expressing "some concern for effects on the brain".[33] In January 2010 the FDA expressed the same level of concern.
A 2007 review has concluded that BPA, like other xenoestrogens, should be considered as a player within the nervous system that can regulate or alter its functions through multiple pathways.[39] A 2007 review has concluded that low doses of BPA during development have persistent effects on brain structure, function and behavior in rats and mice.[40] A 2008 review concluded that low-dose BPA maternal exposure causes long-term consequences at the level of neurobehavioral development in mice.[41] A 2008 review has concluded that neonatal exposure to Bisphenol-A (BPA) can affect sexually dimorphic brain morphology and neuronal adult phenotypes in mice.[42] A 2008 review has concluded that BPA altered long-term potentiation in the hippocampus and even nanomolar dosage could induce significant effects on memory processes.[43] A 2009 review raised concerns about BPA effect on anteroventral periventricular nucleus.[44]
A 2008 study by the Yale School of Medicine demonstrated that adverse neurological effects occur in non-human primates regularly exposed to bisphenol A at levels equal to the United States Environmental Protection Agency's (EPA) maximum safe dose of 50 µg/kg/day.[45][46] This research found a connection between BPA and interference with brain cell connections vital to memory, learning and mood.
Highly controversial claims have been made that BPA could be involved in attention-deficit hyperactivity disorder (ADHD)[47][48][49]
A 2010 study with rats prenatally exposed to 40 microg/kg bw BPA has concluded that corticosterone and its actions in the brain are sensitive to the programming effects of BPA.[50]
A 2005 review concluded that prenatal and neonatal exposure to BPA in mice can potentiate the central dopaminergic systems, resulting in the supersensitivity to the drugs-of-abuse-induced reward effects and hyperlocomotion.[51]
A 2008 review has concluded that BPA mimics estrogenic activity and impacts various dopaminergic processes to enhance mesolimbic dopamine activity resulting in hyperactivity, attention deficits, and a heightened sensitivity to drugs of abuse.[52]
A 2009 study on rats has concluded that prenatal and neonatal exposure to low-dose BPA causes deficits in development at dorsolateral striatum via altering the function of dopaminergic receptors.[53] Another 2009 study has found associated changes in the dopaminergic system.[49]
A 2007 review has concluded that bisphenol-A has been shown to bind to thyroid hormone receptor and perhaps have selective effects on its functions.[54]
A 2009 review about environmental chemicals and thyroid function, raised concerns about BPA effects on triiodothyronine and concluded that "available evidence suggests that governing agencies need to regulate the use of thyroid-disrupting chemicals, particularly as such uses relate exposures of pregnant women, neonates and small children to the agents".[55]
A 2009 review summarized BPA adverse effects on thyroid hormone action.[56]
According to the WHO's INFOSAN, "animal studies have not provided convincing evidence of risk of cancer from BPA exposure."[57]
Neither the U.S. Environmental Protection Agency[58] nor the International Agency for Research on Cancer[59] has evaluated bisphenol A for possible carcinogenic activity.
A 2010 review concluded that Bisphenol A may increase cancer risk.[60]
A 2008 review has concluded that "perinatal exposure to (...) low doses of (..) BPA, alters breast development and increases breast cancer risk".[61] Another 2008 review concluded that " animal experiments and epidemiological data strengthen the hypothesis that foetal exposure to xenoestrogens may be an underlying cause of the increased incidence of breast cancer observed over the last 50 years".[62]
A 2009 in vitro study has concluded that BPA is able to induce neoplastic transformation in human breast epithelial cells.[63] Another 2009 study concluded that maternal oral exposure to low concentrations of BPA during lactation increases mammary carcinogenesis in a rodent model.[64]
A 2010 study with the mammary glands of the offspring of pregnant rats treated orally with 0, 25 or 250 µg BPA/kg body weight has found that key proteins involved in signaling pathways such as cellular proliferation were regulated at the protein level by BPA.[65]
A 2010 study has found that BPA may reduce sensitivity to chemotherapy treatment of specific tumors.[66]
In vitro studies have suggested that BPA can promote the growth of neuroblastoma cells.[67][68] A 2010 in vitro study has concluded that BPA potently promote invasion and metastasis of neuroblastoma cells through overexpression of MMP-2 and MMP-9 as well as downregulation of TIMP2.[69]
A 1997 study in mice has found that neonatal BPA exposure of 2 μg/kg increased adult prostate weight.[70] A 2005 study in mice has found that neonatal BPA exposure at 10 μg/kg disrupted the development of the fetal mouse prostate.[71] A 2006 study in rats has shown that neonatal bisphenol A exposure at 10 μg/kg levels increases prostate gland susceptibility to adult-onset precancerous lesions and hormonal carcinogenesis.[72] A 2007 in vitro study has found that BPA within the range of concentrations currently measured in human serum is associated with permanently increase in prostate size.[73] A 2009 study has found that newborn rats exposed to a low-dose of BPA (10 µg/kg) increased prostate cancer susceptibility when adults.[74]
Bisphenol A suppress DNA methylation (by increased hypomethylation)[75] which is linked to epigenetic changes.[76]
A series of studies made in 2009 found:
A 2010 study with mice concluded that BPA exposure in utero leads to permanent DNA alterations in sensitivity to estrogen.[89]
At an Endocrine Society meeting in 2009, new research reported data from animals experimentally treated with BPA.[90] Studies presented at the group's annual meeting show BPA can affect the hearts of women, can permanently damage the DNA of mice, and appear to be entering the human body from a variety of unknown sources.[91]
A 2009 in vitro study on cytotrophoblasts cells has found cytoxic effects in exposure of BPA doses from 0.0002 to 0.2 micrograms per millilitre and concluded this finding "suggests that exposure of placental cells to low doses of BPA may cause detrimental effects, leading in vivo to adverse pregnancy outcomes such as preeclampsia, intrauterine growth restriction, prematurity and pregnancy loss"[92]
A 2009 study in rats concluded that BPA, at the reference safe limit for human exposure, was found to impact intestinal permeability and may represent a risk factor in female offspring for developing severe colonic inflammation in adulthood.[93]
A 2010 study on mice has concluded that perinatal exposure to 10 micrograms/mL of BPA in drinking water enhances allergic sensitization and bronchial inflammation and responsiveness in an animal model of asthma.[94]
The first large study of health effects on humans associated with bisphenol A exposure was published in September 2008 by Iain Lang and colleagues in the Journal of the American Medical Association.[19][95] The cross-sectional study of almost 1,500 people assessed exposure to bisphenol A by looking at levels of the chemical in urine. The authors found that higher bisphenol A levels were significantly associated with heart disease, diabetes, and abnormally high levels of certain liver enzymes. An editorial in the same issue notes that while this preliminary study needs to be confirmed and cannot prove causality, there is precedent for analogous effects in animal studies, which "add[s] biological plausibility to the results reported by Lang et al."[26]
A later similar study performed by the same group of scientists, published in January 2010, confirmed, despite of lower concentrations of BPA in the second study sample, an associated increased risk for heart disease but not for diabetes or liver enzymes.[96]
Studies have associated recurrent miscarriage with BPA serum concentrations,[97] oxidative stress and inflamattion in postmenopausal women with urinary concentrations,[98] externalizing behaviors in two-year old children, especially among female children, with mother's urinary concentrations,[99] altered hormone levels in men[100][101] and declining male sexual function[102] with urinary concentrations.
The first evidence of the estrogenicity of bisphenol A came from experiments on rats conducted in the 1930s,[103][104] but it was not until 1997 that adverse effects of low-dose exposure on laboratory animals were first reported.[11]
Dose (µg/kg/day) | Effects (measured in studies of mice or rats, descriptions (in quotes) are from Environmental Working Group)[105][106] |
Study Year |
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0.025 | "Permanent changes to genital tract" | 2005[107] |
0.025 | "Changes in breast tissue that predispose cells to hormones and carcinogens" | 2005[108] |
1 | long-term adverse reproductive and carcinogenic effects | 2009[77] |
2 | "increased prostate weight 30%" | 1997[109] |
2 | "lower bodyweight, increase of anogenital distance in both genders, signs of early puberty and longer estrus." | 2002[110] |
2.4 | "Decline in testicular testosterone" | 2004[111] |
2.5 | "Breast cells predisposed to cancer" | 2007[112] |
10 | "Prostate cells more sensitive to hormones and cancer" | 2006[113] |
10 | "Decreased maternal behaviors" | 2002[114] |
30 | "Reversed the normal sex differences in brain structure and behavior" | 2003[115] |
50 | Adverse neurological effects occur in non-human primates | 2008[45] |
50 | Disrupts ovarian development | 2009[78] |
The current U.S. human exposure limit set by the EPA is 50 µg/kg/day.[116]
There is evidence that bisphenol A functions as a xenoestrogen by binding strongly to estrogen-related receptor γ (ERR-γ).[117] This orphan receptor (endogenous ligand unknown) behaves as a constitutive activator of transcription. BPA seems to bind strongly to ERR-γ (dissociation constant = 5.5 nM), but not to the estrogen receptor (ER).[117] BPA binding to ERR-γ preserves its basal constitutive activity.[117] It can also protect it from deactivation from the selective estrogen receptor modulator 4-hydroxytamoxifen.[117]
Different expression of ERR-γ in different parts of the body may account for variations in bisphenol A effects. For instance, ERR-γ has been found in high concentration in the placenta, explaining reports of high bisphenol A accumulation in this tissue.[118]
“ | The problem is, BPA is also a synthetic estrogen, and plastics with BPA can break down, especially when they're washed, heated or stressed, allowing the chemical to leach into food and water and then enter the human body. That happens to nearly all of us; the CDC has found BPA in the urine of 93% of surveyed Americans over the age of 6. If you don't have BPA in your body, you're not living in the modern world. | ” |
Bisphenol A has been known to be leached from the plastic lining of canned foods[120] and, to a lesser degree, polycarbonate plastics, especially those that are cleaned with harsh detergents or used to contain acidic or high-temperature liquids. A recent Health Canada study found that the majority of canned soft drinks it tested had low, but measurable levels of bisphenol A.[121] This exposure through metal cans is due to the fact that BPA is an ingredient in the internal coating of food and beverage metal cans used to protect the food from direct contact with metal. While most human exposure is through diet, exposure can also occur through air and through skin absorption.[122]
Free BPA is found in high concentration in thermal paper and carbonless copy paper, which would be expected to be more available for exposure than BPA bound into resin or plastic.[17][123][124] Popular uses of thermal paper include airline tickets, event and cinema tickets, labels, and point of sale applications (receipts). While there is little concern for dermal absorption of BPA, free BPA can readily be transferred to skin and residues on hands can be ingested.[18]
Studies by the CDC found bisphenol A in the urine of 95% of adults sampled in 1988–1994[125] and in 93% of children and adults tested in 2003–04.[126] Infants fed with liquid formula are among the most exposed, and those fed formula from polycarbonate bottles can consume up to 13 micrograms of bisphenol A per kg of body weight per day (μg/kg/day; see table below).[127] The most sensitive animal studies show effects at much lower doses, while the EPA considers exposures up to 50 µg/kg/day to be safe.[105][128] In 2009, a study found that drinking from polycarbonate bottles increased urinary bisphenol A levels by two thirds, from 1.2 micrograms/gram creatinine to 2 micrograms/gram creatinine.[129]
11 of 13 thermal printing papers contained 8 - 17 g/kg Bisphenol A (BPA). Upon dry finger contact with a thermal paper receipt, roughly 1 μg BPA (0.2 – 6 μg) was transferred to the forefinger and the middle finger. For wet or greasy fingers approximately 10 times were more transferred. Extraction of BPA from the fingers were possible up to 2 hours after exposure.[130]
Consumer groups recommend that people wishing to lower their exposure to bisphenol A avoid canned food and polycarbonate plastic containers (which shares resin identification code 7 with many other plastics) unless the packaging indicates the plastic is bisphenol A-free.[131] The National Toxicology Panel recommends avoiding microwaving food in plastic containers, putting plastics in the dishwasher, or using harsh detergents, to avoid leaching.[132]
A 2009 small US study funded by the EWG has detected an average of 2.8 ng/mL BPA in the blood of 9 out of the 10 umbilical cords tested.[133]
In the US and Canada, BPA has been found in infant liquid formula in concentrations varying from 0.48 to 11 ng/g.[134][135] BPA has been rarely found in infant powder formula (only 1 of 14).[134]
In the US consumption of soda, school lunches, and meals prepared outside the home was statistically significantly associated with higher urinary BPA.[136]
A 2010 study of Austrian, Swiss and German population has suggested polycarbonate (PC) baby bottles as the most prominent role of exposure for infants, and canned food for adults and teenagers.[137]
Population | Estimated daily bisphenol A intake, μg/kg/day. Table adapted from the National Toxicology Program Expert Panel Report.[10] |
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Infant (0–6 months) formula-fed |
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Infant (0–6 months) breast-fed |
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Infant (6–12 months) |
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Child (1.5–6 years) |
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Adult |
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There's no agreement between scientists of a physiologically-based pharmacokinetic (PBPK) BPA model for humans. The effects of BPA on an organism depends on how much free BPA is available and for how long cells are exposed to it. Glucuronidation in the liver, by conjugation with glucuronic acid to form the metabolite BPA-glucuronide (BPAG),[18] reduces the amount of free BPA, however BPAG can be deconjugated by beta-glucuronidase, an enzyme present in high concentration in placenta and other tissues[138][139]. Free BPA can also be inactivated by sulfation, a process that can also be reverted by arylsulfatase C.[138]
The best test methods for studying BPA effects are currently under discussion with scientists sharing different opinions.[140]
A 2010 review of 80+ biomonitoring studies concluded that the general population is internally exposed to significant amounts of unconjugated BPA (in the ng/ml blood range).[141] Using GC/MS on 20 samples, BPA was detected in 100% of urine samples with a median of 1.25 ng.ml, and 10% of blood samples (LOD 0.5 ng/ml).[142]
A 2009 research has found that some drugs, like naproxen, salicylic acid, carbamazepine and mefenamic acid can, in vitro, significantly inhibit BPA glucuronidation.[143]
A 2010 study on rats embryos has found that genistein may enhance developmental toxicity of BPA.[144]
In general, studies have shown that BPA can affect growth, reproduction and development in aquatic organisms. Among freshwater organisms, fish appear to be the most sensitive species. Evidence of endocrine-related effects in fish, aquatic invertebrates, amphibians and reptiles has been reported at environmentally relevant exposure levels lower than those required for acute toxicity. There is a widespread variation in reported values for endocrine-related effects, but many fall in the range of 1μg/L to 1 mg/L.[18]
BPA can contaminate the environment either directly or through degradation of products containing BPA, such as ocean-borne plastic trash.[145]
As an environmental contaminant this compound interferes with nitrogen fixation at the roots of leguminous plants associated with the bacterial symbiont Sinorhizobium meliloti. Despite a half-life in the soil of only 1–10 days, its ubiquity makes it an important pollutant.[146] According to Environment Canada, "initial assessment shows that at low levels, bisphenol A can harm fish and organisms over time. Studies also indicate that it can currently be found in municipal wastewater."[147]
A 2009 review of the biological impacts of plasticizers on wildlife published by the Royal Society with a focus on annelids (both aquatic and terrestrial), molluscs, crustaceans, insects, fish and amphibians concluded that BPA have been shown to affect reproduction in all studied animal groups, to impair development in crustaceans and amphibians and to induce genetic aberrations.[148]
A large 2010 study of two rivers in Canada found that areas contaminated with hormone-like chemicals including bisphenol A showed females made up 85 per cent of the population of a certain fish, while females made up only 55 per cent in uncontaminated areas.[149]
Arguing uncertainty of possible adverse health effects of low dose BPA exposure, especially on the nervous system and on behaviour, and also the differences of exposure of very young children, the WHO announced in November 2009 that it would organize an expert consultation in 2010 to assess BPA safety.[57]
The Australia and New Zealand Food Safety Authority (Food Standards Australia New Zealand) does not see any health risk with bisphenol A baby bottles if the manufacturer's instructions are followed. Levels of exposure are very low and do not pose a significant health risk. It added that “the move by overseas manufacturers to stop using BPA in baby bottles is a voluntary action and not the result of a specific action by regulators.”[1] It suggests the use of glass baby bottles if parents have any concerns.[150]
In April 2008, Health Canada concluded that, while adverse health effects were not expected, the margin of safety was too small for formula-fed infants [151] and proposed classifying the chemical as "'toxic' to human health and the environment."[152]
After the release of that assessment, Canadian Health Minister Tony Clement announced Canada's intent to ban the import, sale, and advertisement of polycarbonate baby bottles containing bisphenol A due to safety concerns, and investigate ways to reduce BPA contamination of baby formula packaged in metal cans. While the agency concluded that human exposures were less than levels believed to be unsafe, the margin of safety was not high enough for formula-fed infants.[27][153] Around the same time, Wal-Mart announced that it was immediately ceasing sales in all its Canadian stores of food containers, water and baby bottles, sippy cups, and pacifiers containing bisphenol A, and that it would phase out baby bottles made with it in U.S. stores by early 2009.[154] Nalgene also announced it will stop using the chemical in its products,[155] and Toys-R-Us said it too will cease selling baby bottles made from it.[156] Subsequent news reports showed many retailers removing polycarbonate drinking products from their shelves.[157]
The federal government has formally declared bisphenol A a hazardous substance as of October 2008 and is now placed on its list of toxic substances. Health officials wrote in Canada Gazette that "It is concluded that bisphenol A be considered as a substance that may be entering the environment in a quantity or concentration or under conditions that constitute or may constitute a danger in Canada to human life or health."[158] The federal ministries of health and the environment announced they would seek to restrict imports, sales and advertising of polycarbonate baby bottles containing BPA.[159]
In its statement Gc.ca released on 18 October 2008, Health Canada noted that “bisphenol A exposure to newborns and infants is below levels that cause effects” and that the “general public need not be concerned”.
On Aug. 25, 2010, Environment Canada confirmed they are in the process of adding bisphenol-A to its list of toxic substances.[ref]http://www.thestar.com/article/852096--in-historic-move-canada-to-list-bpa-as-toxic[/ref]
The updated 2008 European Union Risk Assessment Report on bisphenol A, published in June 2008 by the European Commission and European Food Safety Authority (EFSA) concluded that bisphenol A-based products, such as polycarbonate plastic and epoxy resins, are safe for consumers and the environment when used as intended.[160] By October 2008, after the Lang Study was published, the EFSA issued a statement concluding that the study provided no grounds to revise the current TDI (Tolerable Daily Intake) level for BPA of 0.05 mg/kg bodyweight.[161]
A 2009 scientific study criticized the European risk assessment processes of endocrine disruptors, including BPA.[162]
On 22 December 2009 the EU Environment ministers released a statement expressing concerns over recent studies showing adverse effects of exposure to endocrine disrupters.[163]
The EFSA is scheduled to release another opinion on BPA by May 2010.[164]
In May 2009, the Danish parliament passed a resolution to ban the use of BPA in baby bottles, which has not been enacted by April 2010. In March 2010 a temporary ban was declared by the Health Minister[165]
On March 2010, senator Philippe Mahoux proposed legislation to ban BPA in food contact plastics.[166]
On 5 February 2010, the French Food Safety Agency (AFSSA) questioned the previous assessments of the health risks of BPA, especially in regard to behavioral effects observed in rat pups following exposure in utero and during the first months of life.[167][168] On April 2010 the AFFSA suggested the adoption of better labels for food products containing BPA.[169]
On 24 March 2010 French Senate unanimously approved a proposition of law to ban BPA from baby bottles, the proposition still depends of Assembly approval.[170]
On 19 September 2008, the German Federal Institute for Risk Assessment (Bundesinstitut für Risikobewertung, BfR) stated that there was no reason to change the current risk assessment for bisphenol A on the basis of the Lang Study.[171]
In October, 2009, the German environmental organization Bund für Umwelt und Naturschutz Deutschland requested a ban on BPA for children's products, especially pacifiers,[172] and products that make contact with food.[173] In response, some manufacturers voluntarily removed the problematic pacifiers from the market.[174]
On 6 November 2008, the Dutch Food and Consumer Product Safety Authority (VWA), stated in a newsletter that baby bottles made from polycarbonate plastic do not release measurable concentrations of bisphenol A and therefore are safe to use.[175]
In February 2009 the Swiss Federal Office for Public Health, based on reports of other health agencies, stated that the intake of bisphenol A from food represents no risk to the consumer, including newborns and infants. However, in the same statement it advised for proper use of polycarbonate baby bottles and listed alternatives.[176]
By May 2010 the Swedish Chemicals Agency asked for a BPA ban in baby bottles but the Swedish Food Safety Authority prefers to await the expected European Food Safety Authority's updated review. The Minister of Environment said to wait for the EFSA review but not for too long.[177][178]
In December 2009 responding to a letter from a group of seven scientists that urged the UK Government to ‘adopt a standpoint consistent with the approach taken by other Governments who have ended the use of BPA in food contact products marketed at children’[179] the UK Food Standards Agency reaffirmed in January 2009 their view that ‘exposure of UK consumers to BPA from all sources, including food contact materials, was well below levels considered harmful’.[180]
Between 1998 and 2003, the canning industry voluntarily replaced their BPA-containing epoxy resin can liners with BPA-free polyethylene terephthalate (PET) in many of their products. For other products, they switched to a different epoxy lining that yielded much less migration of BPA into food than the previously used resin. In addition, polycarbonate tableware for school lunches was replaced by BPA-free plastics. As a result of these changes, Japanese risk assessors have found that virtually no BPA is detectable in canned foods or drinks, and blood levels of BPA in people have declined dramatically (50% in one study).[181]
In September, the National Toxicology Program finalized their report on bisphenol A, finding "some concern", mid-point of a five-level scale, that infants were at risk from exposure to the chemical.[33]
At that time, the FDA reassured consumers that current limits were safe, but convened an outside panel of experts to review the issue. The Lang study was also released that month, and David Melzer, a co-author of the study, presented the results of the study before the FDA panel.[182]
The editorial accompanying the Lang study's publication in JAMA criticized the FDA's assessment of bisphenol A: "A fundamental problem is that the current ADI [acceptable daily intake] for BPA is based on experiments conducted in the early 1980s using outdated methods (only very high doses were tested) and insensitive assays. More recent findings from independent scientists were rejected by the FDA, apparently because those investigators did not follow the outdated testing guidelines for environmental chemicals, whereas studies using the outdated, insensitive assays (predominantly involving studies funded by the chemical industry) are given more weight in arriving at the conclusion that BPA is not harmful at current exposure levels."[26]
Sunoco, a producer of gasoline and chemicals, is now refusing to sell the chemical to companies for use in food and water containers for children younger than 3, saying it can't be certain of the compound's safety. Sunoco plans to require its customers to guarantee that the chemical will not be used in children's food products.[183]
The six largest US companies which commercialize baby bottles decided to stop using bisphenol A in their products.[184] Suffolk County, New York banned baby beverage containers made with bisphenol A.[185]
On March 13 leaders from the House and Senate proposed legislation to ban bisphenol A.[186]
In the same month, Rochelle Tyl, author of two studies used by FDA to assert BPA safety in August 2008, said those studies didn't claim that BPA is safe since they weren't designed to cover all aspects of the chemical's effects.[187]
The first US jurisdictions to pass regulations limiting or banning BPA were Minnesota and Chicago. Minnesota's regulation takes effect in 2010, "manufacturers of ... children's products containing BPA may not sell them in the state after Jan. 1, 2010. The ban extends to all retailers in the state a year later." The products impacted are known as sippy cups and baby bottles.[188] The City of Chicago adopted a similar ban shortly thereafter. Coverage of Chicago's ban in the news showed a relentless opposition by the industry. A Chicago Tribune article noted an up-hill battle while passing legislation, "[industry officials] used FDA’s position on the issue when they tried to block the city’s measure."[189]
In May 2009 the Washington Post accused the manufacturers of food and beverage containers and some of their biggest customers of trying to devise a public relations and lobbying strategy to block government BPA bans.[190]
In June 2009, the FDA announced the decision to reconsider the BPA safety levels.[191]
Connecticut was the first US state to ban bisphenol A from infant formula and baby food containers, as well from any reusable food or beverage container.[192]
The California Environmental Protection Agency's Developmental and Reproductive Toxicant Identification Committee unanimously voted against placing Bisphenol A on the state's list of chemicals that are believed to cause reproductive harm. The panel, although concerned over the growing scientific research showing BPA's reproductive harm in animals, found that there was insufficient data of the effects in humans.[193] Critics point out that the same panel failed to add second-hand smoke to the list until 2006, and only one chemical was added to the list in the last three years.[194]
On August 3, Massachusetts' Department of Public Health advised mothers to take certain actions to prevent possible health impact in children. Mothers with children up to two years old were advised to limit exposure by avoiding products that might contain BPA, such as plastic drinking bottles and other plastic materials with recycling codes of 7 or 3.[195]
The Milwaukee Journal Sentinel, as part of an ongoing investigative series into BPA and its effects, revealed plans by the Society of the Plastics Industry to execute a major public relations blitz to promote BPA, including plans to attack and discredit those who report or comment negatively on the monomer and its effects.[196][197]
On September 29, the U.S. Environmental Protection Agency announced that it is evaluating BPA, and another five chemicals, for action plan development.[198]
On October 28, the NIH announced $30,000,000 in stimulus grants to study the health effects of BPA. This money is expected to result in many peer-reviewed publications.[199]
The Consumer Reports magazine published an analysis of BPA content in some canned foods and beverages, where in specific cases the content of a single can of food could exceed the current FDA Cumulative Exposure Daily Intake.[200][201]
On January 15 the FDA expressed "some concern", the middle level in the scale of concerns, about the potential effects of BPA on the brain, behavior, and prostate gland in fetuses, infants, and young children and announced it was taking reasonable steps to reduce human exposure to BPA in the food supply. However, the FDA is not recommending that families change the use of infant formula or foods, as it sees the benefit of a stable source of good nutrition as outweighing the potential risk from BPA exposure.[1]
On the same date the U.S. Department of Health & Human Services released information to help parents to reduce children's BPA exposure.[202]
According to The Milwaukee Journal Sentinel, which supports a BPA ban, after lobbyists for the chemical industry met with administration officials, the EPA delayed BPA regulation and did not include the chemical in an action plan released December 30, 2009.[203][204]
Many US states are considering some sort of BPA ban.[205]
On March 29, the EPA declared BPA a "chemical of concern".[206][207]
The 2008–2009 Annual Report of the President’s Cancer Panel declared: "because of the long latency period of many cancers, the available evidence argues for a precautionary approach to these diverse chemicals, which include (...) bisphenol A"[208]
Meanwhile, as of April, General Mills has announced that they have found a BPA-free alternative can liner that apparently works even with tomatoes, a highly acidic product that has long baffled the industry in terms of finding a suitable substitute. They say with the next tomato harvest, they will begin using it in tomato products sold by their organic foods subsidiary, Muir Glen.[209] Thus far, there has been no word on whether General Mills will use BPA-free alternatives on any of its other canned products.
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