With fall in full force and Thanksgiving looming on the horizon, I started to stock up on some kitchen staples that I don’t buy at other times of the year. A favorite is pumpkin puree that comes in a shelf-stable box, which I use to make soup. During the summer it’s easy to eat mostly fresh food but during the colder months, I admittedly look for a few short cuts. My pumpkin puree got me thinking about aseptic boxed packing, more commonly known by its brand name, Tetra Pak.
I remember when I first started to see items that were typically packaged in aluminum cans cropping up in boxed packaging in the supermarket. I had sworn off canned food because of concerns about BPA in the lining and was happy to have a safer alternative for the few packaged staples I liked to have on hand. But my recent pumpkin purchase got me wondering, just how safe are Tetra Paks?
Tetra Paks are made with 75% paperboard, 20% polyethylene, and 5% aluminum and the layers are adhered using heat and pressure. Polyethylene is the only material that comes in contact with food. Food-grade polyethylene is considered one of the safest plastics but, as I wrote about in this post, even plastics thought to be safe can leach chemicals with estrogenic activity.
I only found one study that specifically tested Tetra Paks and it concluded that Tetra Paks showed estrogenic contamination similar to that from plastic water bottles. So, are they any safer than cans? Cans with BPA lining have been widely tested and are known to leach BPA. The evidence is clear that they are best avoided. Read more here about BPA-free cans and why they may not be any safer. The evidence is not as clear for Tetra Paks, but there is enough to cause concern. I’ll be keeping my purchases of boxed shelf-stable food to a minimum. Fortunately, more products are being introduced in glass jars, such as organic diced tomatoes, ready-made soups, and nut milks. Glass is the safer choice.