You've decided to go BPA free and are feeling pretty good about yourself as you clean out the cupboards and shop for better alternatives. Well the first thing to know is that it is nearly impossible to find such a thing as a totally 'safe' plastic.The thing is that even if the plastic is 'safe' (think numbers 1,2 and 5), every piece of plastic has additives and it's the additives that are the biggest problem. Additives are the manufacturers proprietary secret, but a single plastic item like a take away food container can house up to 25 or more additives and a multiple plastic like a baby's bottle, up to 100.The basic problem is that while a barefoot polymer (the raw plastic) might not leach any kind of Estrogenic Activity (EA), pretty much every imaginable additive, according to a 2011 study by University of Texas et al, actually does. This essentially means that even if you find BPA free plastic, Bio-Plastic (like that made from corn) or you are using an apparently 'safe' plastic, you are still being exposed to EA. Worse, the study found that some BPA replacement plastics like baby bottles made from polyethersulfone (PES) actually leached more EA than the BPA product they are replacing. Stressed plastic - or plastic heated in a microwave, by sitting around in a hot car or filled with hot contents is more likely to leach EA than non stressed. In the end, it is better to use glass or metal containers. If you must use plastic, especially as the science improves, go for products claiming that they are 'EA Free'. Excerpt from the Study:'Our data show that most monomers and additives that are used to make many commercially available plastic items exhibit EA. Even when a “barefoot” polymer (no additives) such as PE or polyvinyl chloride does not exhibit EA, commercial resins and products from these polymers often release chemicals (almost certainly additives) having EA.We found that exposure to one or more common-use stresses often increases the leaching of chemicals having EA. In fact, our data suggest that almost all commercially available plastic items would leach detectable amounts of chemicals having EA once such items are exposed to boiling water, sunlight (UV), and/or microwaving.'Image: Creativa Images/Shutterstock