I dont know about you, but I am deeply troubled and concerned about the debate raging today concerning bisphenol-A (BPA). My concern is not so much that there is another common chemical that may produce public health problems but it is about how politics and marketing have rushed in to "support" the science.

It seems that there are two distinct camps in this argument and very little space between them. The pro-BPA camp says that BPA is the most tested material to date, and it has been safely used for more than 50 years. The anti-BPA camp claims that it deserves more study even though research has been going on for more than 10 years, studies number in the hundreds, and millions of dollars have been spent.

This is an important debate since bisphenol-A is an essential basic building intermediate for polycarbonate plastic and epoxy resins, and nearly everyone is exposed to these materials. Around 80% of the BPA is used to produce polycarbonate plastic which is commonly used in consumer applications such as baby bottles, food containers, and packaging. However, epoxy resins also use BPA. The main concern with BPA in epoxy resins is that it is commonly used for coatings in food cans.

In 2010, the U.S. FDA indicated that it shares concerns over the use of BPA, but didnt recommend discontinuing the use of products that contain BPA. In the meantime the Environmental Protection Agency has announced plans to consider adding BPA to its list of chemicals of concern and study levels of BPA in surface, ground, and drinking water.

Legislatures in several countries are considering banning BPA in childrens products. The European Commission voted to ban BPA from plastic baby bottles by the middle of the year. Canada, France, and Denmark already have banned the use of BPA in baby bottles. The World Health Organization has held meetings with the United Nations Food and Agriculture Organization to discuss the health effects of BPA and possible substitutes.

Some businesses are being proactive to this matter. Sunoco, for example, has announced that it will not sell the chemical to customers whose products might expose infants or small children. The massive retailer Wal-Mart no longer sells baby bottles made with BPA and other retailers are following this initiative. Most baby bottle makers have stopped using BPA, and canned food makers have also begun to use non-BPA linings.

But what does this mean to the epoxy and more specifically the adhesive communities? Epoxy resins have many engineering applications including printed circuit boards, composites, paints, and adhesives. Cured epoxy resins are generally inert materials and have achieved wide acceptance due to their unique combination of toughness, adhesion, formability, and chemical resistance. There are alternatives to BPA polycarbonate in food packaging. One is polyethylene terephthalate (PET) which is cheaper and more recyclable although not as durable, clear, or heat-resistant. There are also some alternatives to BPA epoxy in can linings. In Japan, for example, food canners have begun to use PET linings and epoxy with much less BPA than was used previously.

It is apparent that the major concern is the migration of BPA out of plastics especially in products that are accessible to children, pregnant women, etc. Fortunately, most epoxy applications utilize BPA as a completely reacted product. Migration is therefore limited and any exposure would be miniscule. Even the levels that have been detected in canned foods are unlikely to be of concern to health. Yet, migration and degradation of epoxy systems can occur depending on the application and method of disposal, and the release of BPA to the environment may be possible in some situations.

One can only continue to watch the testing and regulatory efforts that are going on with polycarbonate plastic and try to extrapolate them to epoxy resins. This is difficult for a number of reasons. Concerns about BPA stem from studies on lab animals, but whether it does any harm in people is unclear. Experiments on humans are unethical unless there is a possibility of medical benefit. Also some of the effects that scientists fear from BPA would not show up for decades, until a child who was exposed in the womb grew up. It is also difficult if not impossible to find a "control group" since the U.S. Center for Disease Control and Prevention found that more than 90% of the general population had BPA in their urine.

Over the next few years, researchers hope to bring closure over this debate. However, I have my doubts as it appears the pens of the legislators and marketing people may prove stronger than the test tubes of scientists.