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It's well documented that BPA was first synthesized by chemists in 1891, however, the first mention of BPA was made in a scientific paper in 1905 by Thomas Zincke of the University of Marburg, Germany.
It wasn't made relevant until the 1950s when the thriving plastic industry underwent a technology revolution with the introduction of new materials, design techniques, and processes, such as injection molding.
Dr. Hermann Schnell of Bayer invented polycarbonate (PC) resin in 1953, just one week before chemist Dr. Daniel Fox of GE made the same discovery while working on developing a new wire insulation material. Both found a gooey substance that hardened in a beaker, and despite their best efforts, they could not break or destroy the material. They were equally impressed by the toughness of the material.
While both companies applied for U.S. patents in 1955, they agreed the patent holder would grant a license for an appropriate royalty, which allowed both companies to concentrate on developing the polymer.
The main polycarbonate material is produced by the reaction of BPA and phosgene COCl2. Unlike most plastics, polycarbonate can undergo large plastic deformations without cracking or breaking.
Polycarbonate was initially used for electrical and electronic applications such as distributor and fuse boxes, displays and plug connections and for glazing for greenhouses and public buildings. PC's characteristics became popular for many other applications, including plastic bottles and linings for metal-based food and beverage cans.
The use of PC for food packaging received original approval in the 1960s by the FDA under its food additive regulations.
Throughout the decades there were various studies with regards to BPA, but it wasn't until medical doctor David Feldman, a professor at Stanford University, made a discovery that changed the discussion of PC and BPA forever.
"We weren't looking for this," he says. "It was basically an accident."
During the early 1990s, Dr. Feldman conducted studies on estrogen activity. In 1992, Feldman and his team discovered what looked like an estrogenic molecule when they were growing yeast in plastic flasks. It turned out it was not the yeast synthesizing the estrogen, but rather it was leaching from the plastic. The team then performed an experiment without having the yeast in the flask, and they found there was still this estrogenic molecule in the medium, which they then identified the estrogenic molecule as BPA. They found it was coming from the plastic flask and was not present when they did the experiment in glass flasks.
"We realized that we had identified a molecule that was leaching out of the plastic that, due to its estrogenic hormone-like properties, was potentially dangerous to people eating out of containers made of this type of plastic," he says.
Once they made the connection between polycarbonate, BPA and estrogenic activity, Feldman and his team contacted a major producer of PC, the former GE Plastics, now Sabic Innovative Plastics, the producer of the Lexan brand PC.
It turns out the company had already looked into the potential leeching issue, but after using their own methods, they said they couldn't find any estrogenic activity.
While Feldman and his team wrote about their findings, he moved on from conducting research on BPA, but he continued to study findings out of an interest.
"We are still in the same place we were 20 years ago," Feldman says with a sigh. "We are still exposed to this molecule in our food supply, it's in our urine. The question of how bad it is, well, it's still debated."
Bans began with what some called "defending" the most helpless of people—infants.
A 2008 report by the U.S. National Toxicology Program (NTP) found "some concern for effects on the brain, behavior, and prostate gland in fetuses, infants, and children at current human exposures to bisphenol A," with that exposure coming from PC baby bottles and infant cups.
Once baby bottles that were microwaved were found to release BPA into infants' milk, the European Union and Turkey banned the chemical from baby bottles in 2008. Canada also banned BPA in bottles, with Health Canada concluding that chemical was "'toxic to human health and the environment."
Denmark has banned BPA in all baby food products, and the Japanese canning industry has replaced its BPA-containing resin can liners. The U.S. still allows BPA in baby bottles, but 11 U.S. states have prohibited the use of BPA in children's products.
The FDA states on its website that it "supports the industry's actions to stop producing BPA-containing baby bottles and infant feeding cups for the U.S. market, along with facilitating the development of alternatives to BPA for the linings of infant formula cans."
BPA TIMELINE: FROM INVENTION TO CONTROVERSY
Russian chemist Aleksandr Dianin first synthesizes BPA in a laboratory.
The first mention of BPA was made in a scientific paper by Thomas Zincke of the University of Marburg, Germany.
British chemist Charles Edward Dodds recognizes BPA as an artificial estrogen.
Polycarbonate (PC) resin is invented in 1953 by two chemists working at different companies. While both companies apply for U.S. patents in 1955, they agreed that the patent holder would grant a license so both companies could develop the polymer.
BPA begins to appear in PC consumer products throughout the world.
The FDA approved the use of BPA in consumer products like PC water bottles, baby bottles, food containers and epoxy linings for metal-based food and beverage cans.
Dr. David Feldman of Stanford University discovers BPA has migrated from his PC test tubes into a test specimen and appears to be mimicking estrogen. He becomes the first researcher to identify and call attention to the possible impact of low levels of PC component BPA on human health.
According to Environmental Working Group (EWG), an American environmental organization, a memorandum from the FDA technical staff estimates that through contaminated canned food, adults are exposed to 11 micrograms of BPA daily, while infants are exposed to 7 micrograms per day.
University of Missouri-Columbia finds that low-level exposure to BPA may harm the prostate, which became one of many studies from around the world that linked BPA to an array of health effects.
Over the next decade, reports on low-dose BPA toxicity will grow to include more than 100 publications.
Due to consumer concern about the toxic effects of BPA, Japanese industries voluntarily reduced the use of BPA between 1998 and 2003.
The canning industry in Japan replaces its BPA-containing epoxy resin can liners with BPA-free polyethylene terephthalate (PET) in many products. 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 the Japanese people have declined.
The European Commission and European Food Safety Authority (EFSA) says BPA-based products, such as polycarbonate plastic and epoxy resins, are safe for consumers and the environment when used as intended.
Health Canada releases results of its human health screening assessment on BPA. It declares BPA "toxic" because of reproductive and developmental toxicity and environmental effects. The country bans the import, sale and advertising of polycarbonate baby bottles containing BPA due to these concerns.
A report by the U.S. National Toxicology Program (NTP) found "some concern for effects on the brain, behavior, and prostate gland in fetuses, infants, and children at current human exposures to BPA," with that exposure coming from PC baby bottles and infant cups.
Between the Health Canada announcement and the NTP findings, a majority of retailers and bottle manufacturers switch from PC to alternatives. Wal-Mart Stores Inc. and Toys "R" Us begin phasing out bottles, sippy cups and other children's items containing BPA.
SIGG reusable aluminum water bottles are found to contain BPA in the liner, even though the company previously said they didn't. The media blitz surrounding this fuels consumer fears about the potential danger of BPA in plastic and, now, metal packaging.
The Natural Resources Defense Council (NRDC) takes a stand against BPA as a whole, and asks the FDA to eliminate the chemical from all food packaging.
Six U.S. companies that produce baby bottles decide to stop using BPA in their products.
The Endocrine Society publishes its scientific report on endocrine-disrupting chemicals that says there is strong evidence chemicals that interfere with the hormone system can cause serious health problems. It recommends people take a "precautionary approach" by reducing their exposures.
The National Institutes of Health is awarded $30 million in research grants to research the potential health effects of BPA.
In November, Consumer Reports releases a new study about the dangers of BPA from canned foods and cautions readers to "seek alternatives," including using glass containers when heating food in the microwave.
FDA joins other health agencies to express "some concern" over BPA safety. FDA supports industry's actions to remove BPA from baby bottles, feeding cups, the lining of formula cans and other food cans, but does not provide any details or a timeframe for these voluntary actions.
Heinz removes BPA from cans sold in Australia, the U.K. and Ireland.
Health Canada releases new study of BPA exposure levels in canned foods. Its conclusion is "that current dietary exposure to BPA through food packaging is not expected to pose a health risk to the general population, including newborns and infants."
European Union bans BPA in baby bottles.
China proposes to ban BPA in anything used to contain food or drink for children.
About 26 U.S. states propose legislation that would ban certain uses of BPA. Many bills fail, but some are moving forward.
The NRDC sues the FDA, and asks the court to compel the agency to respond. The court eventually issues a consent decree requiring FDA to make a final decision on NRDC's petition by Mar. 31, 2012.
2012 and beyond
March 31 arrives, and the FDA ultimately decides not to ban BPA from food and beverage packaging.
Currently 11 states have banned BPA from baby bottles and children's sippy cups. California passes the Toxin-Free Infants and Toddlers Act, banning BPA from baby bottles and children's sippy cups.
The American Medical Assn. announces its support of tighter restrictions on products containing BPA.
Campbell Soup announces it will phase out the use of the BPA in its can linings.
France votes to ban BPA in all food containers by Jan. 1, 2014, and by Jan. 1, 2013, for food packages, materials and containers for infants and young children.
In March, Rep. Edward Markey (D-MA) asks the FDA to ban the chemical's use in formula containers, reusable food containers and in canned foods and beverages. The last two petitions are rejected, but the FDA accepts the petition on infant formula, and says it plans to collect comment from the public before making a final decision. The FDA says it will try to complete a scientific review within the next 90 days.
Image: BlendE11/Adobe Stock
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