Tag Archives: polycarbonate

Article misleads on BPA alternatives.

By Laura Vandenberg Aug 02, 2010 06:00 AM | Permalink

In reviewing a proposed bill to ban BPA from food and beverage containers, a San Francisco Chronicle article presents a one-sided view of available alternatives.

San Francisco Chronicle article describes efforts by U.S. Representative Dianne Feinstein to pass a bill banning bisphenol A (BPA) from food and beverage containers. Unfortunately, the reporter relies on information provided by industry officials to explain the availability of BPA-free alternatives. This one-sided approach misinforms readers.

Reporter Carolyn Lochhead states that “With no viable alternative for can liners, an immediate ban would be equivalent to banning canned foods.” An industry spokesman adds that “banning [BPA] would make food less safe because there is no viable alternative to line cans and jars.”

These statements stretch the truth. There are, in fact, food cans on the market without BPA in their epoxy linings. Some BPA-free cans are made with a vegetable-based lining that was used by the canning industry before the switch to BPA-based resins. These have been used for more than a decade.

Lochhead interviewed only a few sources for her story: Representative Feinstein; a U.S. Food and Drug Administration representative; and the director of the American Chemistry Council, an industry lobbying group. The important voice that is missing is an independent scientist. A scientist who works on BPA could have pointed out the alternative cans that exist and provided better accuracy in reporting the effects of BPA on animals and humans.

Human exposure to BPA is widespread through food can linings, polycarbonate plastics, some thermal papers and dental sealants, among other sources. A 2008 study by the US CDC showed that almost everyone has this chemical in their bodies. Reducing or eliminating BPA in consumer products can have a significant impact on human exposures. A 2003 study found that BPA levels in urine collected from Japanese college students in 1999 dropped compared to levels measured from similar students in 1992. During this period of time, the authors report that some can linings were changed from a BPA-based resin to a lining that eliminated or reduced the use of BPA.

BPA has been linked to numerous adverse health effects in exposed animals, including malformations of the male and female reproductive tract, changes in the development of the brain, alterations in the immune system, development of prostate and mammary cancers, and changes in behavior, among others. BPA studies in humans, while limited, also suggest that this chemical could have adverse health effects.

Dream of plastics from carbon dioxide is a reality.

Dream of plastics from carbon dioxide is a reality.

Jun 01, 2010

Zhang, Y and J Young Gerentt Chan. 2010. Sustainable chemistry: imidazolium salts in biomass conversion and CO2 fixation. Energy and Environmental Science http://dx.doi.org/10.1039/b914206a.

Synopsis by Adelina Voutchkova
Certain classes of organic molecules can be instrumental in both capturing carbon dioxide from the air and incorporating it into new plastic materials, which could lessen the need for raw petroleum.

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Chemists have made progress in finding environmentally friendly ways to capture and reuse carbon dioxide (CO2). Specifically, significant new advances have been made in the ability to absorb CO2 from the atmosphere and incorporate it into new raw materials – including benign alternatives to BPA-based plastics.

Certain classes of organic molecules have been discovered to be instrumental in capturing carbon dioxide from the air and incorporating it into new plastic materials. This process eliminates petroleum as an input, and generates more benign materials in the process.

In this and several other recent articles, researchers report how a class of chemicals – called “ionic liquids” – can efficiently capture and incorporate CO2 into chemicals, which can then be turned into a plastic. Such plastics can contain about 40 percent by weight of incorporated CO2.

CO2 is an excellent chemical building block; it is renewable, abundant and considered environmentally friendly. Plants efficiently convert CO2 into food through photosynthesis. Scientists, however, have long struggled to reproduce this process at an industrial scale. Before recent advances, the methods that existed were very inefficient, rendering them economically unviable.

Two research groups may have stumbled on a much more efficient method. Using chemicals called imidazoliums and N-heterocyclic carbenes (NHCs), researchers in Singapore report they were able to couple CO2 with molecules called “epoxides” to form polycarbonates – plastics used in everything from water bottles to compact disks. Importantly, in addition to finding a new use for carbon dioxide, these polycarbonates do not contain bisphenol A. It turns out that while virtually all commercial polycarbonate plastics today are made using bisphenol A as the basic building block, there are alternatives, as demonstrated by this research.

The imidazolium salts are stable chemicals that can repeatedly “grab” CO2 molecules and hand them over to be incorporated into bigger molecules. This makes them valuable in processes that convert CO2 to other chemical products as well. In addition, they are more benign and the reactions less severe than the metals typically used.

In sum, this research demonstrates two significant advances, first in demonstrably moving forward the capacity to harness and use CO2 in industrial applications, second in its successful application in developing a benign alternative to a problematic chemical.

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1 June Dream of plastics from carbon dioxide is a reality. Chemists have made progress in finding environmentally friendly ways to capture and reuse carbon dioxide. New advances have been made in the ability to absorb CO2 from the atmosphere and incorporate it into new raw materials – including benign alternatives to BPA-based plastics. Environmental Health News.

16 December How to make plastic with less petroleum–just add CO2. Using technology developed at Cornell University, Novomer gets additional funding to develop a plastic-manufacturing process that requires less oil by folding in carbon dioxide. Scientific American.

10 April New process converts C02 into plastic products. If plans to remove carbon dioxide–the primary greenhouse gas –from smokestacks succeed, the gas could be harnessed and turned into plastic products, new research claims. Xinhua News Agency, China.

9 April CDs and DVDs to be made with CO2 emissions. Scientists have devised a new way to enable pop groups and film stars with a conscience to save the planet: Their CDs and DVDs can now be made from carbon dioxide. London Daily Telegraph, United Kingdom.

6 May What can we do with carbon dioxide? Scientists are trying to find ways to convert the plentiful greenhouse gas into fuels and other value-added products, some saying that target areas should focus on using CO2 to replace large-volume starting materials derived from petroleum and natural gas. Chemical & Engineering News.