A second look at BPA

Wherever I can, I use tap water instead of bottled. For most flights, I'll carry my empty bottle through security and fill it up on the other side. Airports with bottle filling stations are my favorite. I've even filled my water bottle up with tap water from the Flint airport (I was assured the water was safe) . Over the holidays, I left my trusty nalgene bottle at my family home. As I'll be able to pick it up the next time I visit home, I saw no need to buy a new one. Until then, I'll just be using the near identical bottle I keep with my camping gear. In fact, there is only one major difference between the two bottles. The new one is "BPA free", while the old one most definitely has BPA. Since I planned to use this bottle for the next month, I decided to take a second look at BPA.

Time for a little chemistry

Chemistry has never been my favorite subject (I prefer physics), but it pops up often in my work as a materials engineer. I don't work with food grade plastics, so I had to do a little reading. BPA stands for Bisphenol A (chemical formula (CH₃)₂C(C₆H₄OH)₂ ). BPA is the most common member of the bisphenol family. Bisphenols are chemical compounds with two two hydroxyphenyl functionalities [1]. All that means is that bisphenols have two functional groups to bond with other organic compounds.

BPA's most widely publicized use was in plastic bottles. Most of these bottles are made from polycarbonate, commonly referred to by the trade name Lexan. Polycarbonate is a strong and optically clear material that can be easily molded. Polycarbonate bottles are great. You can drop them off cliffs, back over them in your car, bang them against rocks and they won't break. Unfortunately, they may also cause cancer (and what doesn't cause cancer these days?). If you have an old bottle and want to check if it has BPA, polycarbonate will be marked with a #7 recycle code and may also say "PC".

BPA can also be used on thermal paper (think receipts) and also the epoxy resin liner for can and food pouches. Unlike the BPA used in polycarbonate [2], thermal paper contains unpolymerized BPA. This means that tiny amounts of BPA can be directly transmitted to your skin [3]. Overall, about 2.5 billion pounds of BPA are used each year in the U.S. alone! About 5% of that amount ends up in food contact [4].

Is BPA really that bad?

Based on some government reports and news articles from 2008 - 2010, BPA got a lot of bad press. Because BPA has a similar structure to estrogen, agencies were concerned about the health consequences of high BPA levels. BPA can leach out of the bottle, especially with hot liquids. However, there never really was a clear link establishing BPA to any health issues in people. In 2015, the European Food Safety Authority actually published a statement that current BPA levels posed no health risk [5]. Also, plastics manufacturers simply switched to a different bisphenol to replace BPA. Many are now using the very similar bisphenol S and slapping a "BPA Free" sticker on their products [6].

The solution

Based on my reading, I don't really see a difference between using my old or new water bottles. Ultimately, I would like to move away from plastic altogether. I have switched from plastic food containers to glass. I now do most of my cooking on cast iron instead of nonstick pans. I have tried using a stainless steel bottle in the past and did not like the poor insulation and metallic taste. If you have a recommendation for a bottle that you like, please let me know in the comments.

---

Happy New Year everyone! I am looking forward to 2017 and continuing to post here on Steemit. About me and my story. Vir@tutanota.com