24 March 2010 11:37 [Source: ICB]
While the safety of bisphenol A is being hotly debated, development of alternatives is on the rise
CONFUSION REIGNS when it comes to the health and safety issue of bisphenol A (BPA), a key ingredient in the production of epoxy resins being used in the linings of canned food packaging, and polycarbonate (PC) resins, which are used in baby bottles, water bottles and sippy cups.
Rex Features/Chris Eyles
The latest BPA study was published on March 9 by researchers from the Swiss Federal Institute of Technology, based in Zurich. It examines 17 different sources of potential BPA exposure across nine different consumer groups in the German/Swiss/Austrian population. The researchers conclude that PC baby bottles are the most relevant BPA exposure source for infants and children, and consumption of canned food for teenagers and adults.
Estimated BPA levels found in the study are well below the Tolerable Daily Intake (TDI) of 50 micrograms/kg body weight per day set by the European Food Safety Authority (EFSA). "However, it is of the same order of magnitude as recently reported concentrations that caused low-dose BPA health effects in rodents," the study notes.
Several studies came out in 2009 focusing on chronic exposure of rodents to low doses of BPA, and some concluded impairment in the growth and function of the rodents' reproductive cells.
"It seems that nearly every week there's a new study linking BPA to a disease or disorder - from cancer to infertility, diabetes and obesity, to heart disease - which has shaken any belief that BPA is safe for use in consumer products," says Margie Kelly, spokesperson for US-based consumer watchdog group Safer States.
"The chemical industry should be searching for safer alternatives"
Margie Kelly, spokesperson, Safer States
"The chemical industry should be assuring the public that it is aggressively searching for safer alternatives to BPA in baby products and canned food packaging both to prevent liability and to restore consumer confidence in these products," she adds.
Trade body the American Chemistry Council (ACC) emphasizes that BPA, which has been in use since the 1950s, is one of the most thoroughly tested chemicals in commerce today, and that regulators from around the world have reaffirmed BPA's safety.
The latest study confirming its safety was published on February 17 by US-based WIL Research Laboratories. The study, which examines pregnant rodents to a range of BPA doses from low to high, concludes that BPA had no effects on brain development or behavior in those of their offspring that had been exposed to BPA.
The ACC notes that this study reaches the same conclusion as that of the low-dose BPA study reported by the US Environmental Protection Agency (EPA) in October 2009.
"A consumer would have to ingest more than 500 pounds of food and beverages in contact with BPA every day for a lifetime to exceed EFSA's TDI," says Steve Hentges, head of the ACC's Polycarbonate/BPA Global Group. "Consumer exposures to BPA from all sources [are] low and these exposures are well within the limits that regulatory agencies have established as safe for consumers - both adults and children."
FDA IN THE MIDDLE
All eyes, however, are on the US Food and Drug Administration (FDA) this year as the agency, in cooperation with the National Toxicology Program (NTP) of the Department of Health and Human Services, is also carrying out in-depth studies to clarify uncertainties about BPA's risks. The results of the research are expected to be available within 18-24 months.
While the FDA continues to support the safety of BPA, the agency decided in January to do additional research after the NTP completed a BPA review in September 2008 expressing "some concern" for its effects on the brain, behavior and prostate glands in fetuses, infants and children at current doses. The NTP recommends additional research is needed to fully assess BPA's risks.
"Some concern means that we need to know more," Joshua Sharfstein, the FDA's principal deputy commissioner said during a press conference held on January 15. "If we thought it was unsafe, we would be taking strong regulatory action."
Still, the FDA said it is taking reasonable steps to help reduce human exposure to BPA. Some of the steps recommended by the agency include supporting the industry's action to stop producing BPA-containing baby bottles and infant feeding cups to the market; facilitating the development of BPA alternatives for the linings of liquid infant formula cans; and supporting efforts to replace BPA or minimize BPA levels in other food can linings.
"There is an opportunity for the chemical industry to save the day here"
Emily Stone, shareholder advocate, Green Century
The ACC, as well as the North American Metal Packaging Alliance (NAMPA) express their support for the FDA's quest for more BPA research. However, the ACC says it is disappointed with some of the FDA's recommendations, which it says are not well-founded and likely to worry consumers.
More and more BPA-free infant care products are coming out on retail shelves as several manufacturers such as US-based Playtex, Gerber and Nalgene, and even major retailers such as Walmart, Toys "R" Us, and Whole Foods decided to stop selling PC baby bottles.
"The voluntary withdrawal of PC baby bottles by manufacturers is a market-driven development," says Jasmin Bird, spokesperson for Belgium-based trade group PlasticsEurope.
"From a scientific, safety and regulatory perspective, it is unnecessary. Still, in a free market, it is normal that there are continuous efforts to develop technically improved or innovative products," she adds.
Alternatives to PC resins include high density polyethylene (HDPE), metallocene polypropylene (PP), polyethylene (PE) naphthalene, polyethersulfone, and US-based Eastman Chemical's Tritan copolyester, according to a December 2009 report from global consultancy Nexant.
A clear winner has been Tritan, which reportedly sold out shortly after the BPA issue erupted last year, says Michael Brown, president of US-based consultancy StrategyMark. "Its success has been largely due to its drop-in match of physical and processing properties versus [PC]," he notes. "PP resin is likely the second winner in this space - not only due to the BPA issue, but also a trend toward reducing material costs," Brown adds.
Eastman launched Tritan in the infant care market in October 2008. Since then, it has been used in reusable bottles, pacifiers, breast pumps, plastic dishware and cutlery. Sales quadrupled during the past 12 months, says Lucian Boldea, business director for Eastman's specialty plastics business.
"We have seen that marketplace demand for consumer products made without BPA has increased," says Boldea. "Our outlook for sales looks good as we have started to work with numerous new brands that need sizeable amounts of Tritan for innovative applications."
But the picture for alternatives to epoxy resins in metal can linings is quite different.
"Alternatives for epoxy resins in can coatings are rather limited, but include polyester, polyacrylate, alkyd resins and polyvinyl chloride [PVC] organosols. None of these resins are exact drop-ins for epoxy," says Brown. "Each would require a substantial trade-off in cost, processability and potential capital investment for the can maker." He adds that some of the alternatives may even have their own health issues.
NAMPA chairman John Rost echoes the same concern. "NAMPA is aware of consumers' increasing demand for alternative coatings for metal packaged foods, despite BPA's record of success," he says. "NAMPA members are engaged in research programs to deliver those alternatives to consumers who request them. This must be done in the safest manner possible and not be immediate due to testing requirements and regulatory procedures to ensure the safety of any new product."
NAMPA reiterates the unprecedented safety record of BPA when it comes to protecting food from safety issues like food-borne illnesses. "Whether industry is able to develop an alternative that allows for the same level of shelf-life afforded by epoxy resin is yet to be seen," Rost notes.
Like most environmental advocacy groups, US investment advisory firm Green Century Capital Management believes that a BPA ban at both the state and federal level is key in spurring a large-scale transition to BPA-free alternatives, especially in metal can linings.
The group acknowledges the limited existence of alternatives in metal can linings but notes that the packaged food industry has been actively exploring alternatives for years.
Emily Stone, shareholder advocate for Green Century, cites US food companies Hain Celestial and Heinz, and Switzerland's Nestle as examples of companies that previously announced plans to phase out BPA in some of their products.
"We found that nearly every packaged food company that we are in dialogue with is telling us that they will implement an alternative if they have one that works," says Stone. "There is an opportunity for the chemical industry to essentially save the day here by positively and visibly contributing effective resources to the efforts in finding BPA alternatives."
Regulatory actions, she adds, are likely to speed up the inevitable transition to BPA-free materials. US states such as Minnesota and Connecticut already passed bans in 2009 on the manufacture and sale of BPA-containing bottles and containers that are intended for use by children, specifically aged three years or younger for Minnesota.
Wisconsin passed its own ban in March 2010, while legislative bodies from Washington State and Maryland are considering a similar BPA ban this year. The Minnesota prohibition took effect in January, and the Wisconsin and Connecticut bans will respectively go into effect by June 2010 and October 2011.
"If BPA and related industry lose the battle of public opinion, which will likely play out completely over the next few months, it is likely we will see [PC] continue to lose share in consumer-related products, particularly food/beverage contact applications," says Brown. PP will increase market share if displacement of PC expands beyond food and beverage use, he adds. An industry source says PC use in food containers in the US in 2009 accounted for less than 10% of total use.
No bans are being considered for epoxy resins in canned food linings because of the difficulties in finding replacements. Any BPA ban is most likely to affect consumers directly, says Rost.
"If a ban was to go into place prior to availability of any fully developed and tested alternative coatings, one result would likely be significant decreases in shelf life of the packaged food," he says. "This decrease would dramatically increase the amount of food waste, therefore increasing overall food cost for everyday consumers."
CORN-BASED EPOXY AS AN ALTERNATIVE
The Iowa Corn Promotion Board (ICPB) of the US agricultural cooperative Iowa Corn Growers Association jointly filed a patent with the New Jersey Institute of Technology (NJIT) in February for a corn-derived epoxy resin that may be able to replace bisphenol A (BPA)-based epoxies.
Developer Michael Jaffe, a professor of biomedical engineering at NJIT, says the epoxy resin is specifically derived from corn-based isosorbide diglycidyl ether. Both components of the epoxy - the resin and the hardener - are from water-soluble, plant-derived chemistries, he says.
"The next steps are to validate the material performance in partnership with appropriate companies in the epoxy industry. This involves materials scale-up and industry-relevant testing of both materials performance and materials safety," Jaffe adds.
The epoxy product was the first in a series of patents filed in partnership with the ICPB to develop applications and markets for sugar-based chemistry. The epoxy resin research was initiated four years ago. The partnership is already in dialogue with food packaging companies, as well as several chemical companies, says Jaffe.
"If all goes well, we envision commercialization to take place within a two to three-year timeframe," he says. "A big challenge is to make suitable volumes of the material available at attractive pricing and to create an industry-relevant database that qualifies the product in food contact applications."
And food contact applications are not their only focus. The epoxy resin will also be tested to verify that it will meet specifications for a broad range of applications.
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